Tissue model dynamic visual rendering

ABSTRACT

Disclosed herein is a method of graphically presenting an indicating marker over a 3-D model of a tissue surface during a catheterization procedure, comprising determining a region over the 3-D model, deforming the indicating marker to congruently match a shape defined by the 3-D model across the region at a plurality of positions; and rendering the 3-D model into an image including the deformed indicating marker by generating an image of the 3-D model covered by said deformed indicating marker.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/461,384 filed on May 16, 2019, which is a National Phase of PCTPatent Application No. PCT/IB2017/057169 having International FilingDate of Nov. 16, 2017, which claims the benefit of priority under 35 USC§ 119(e) of U.S. Provisional Patent Application No. 62/422,708 filed on16 Nov. 2016, U.S. Provisional Patent Application No. 62/422,705 filedon 16 Nov. 2016 and U.S. Provisional Patent Application No. 62/422,713filed on 16 Nov. 2016. The contents of the above applications are allincorporated by reference as if fully set forth herein in theirentirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to systemsand/or methods for assisting a surgeon in catheterization procedures,more particularly, but not exclusively, to such system and/or methodsthat make use of dynamic visual representations.

U.S. Patent Application Publication No. 2003/074011 discloses “A methodof displaying at least one point-of-interest of a body during anintra-body medical procedure. The method is effected by (a) establishinga location of the body; (b) establishing a location of an imaginginstrument being for imaging at least a portion of the body; (c)defining at least one projection plane being in relation to a projectionplane of the imaging instrument; (d) acquiring at least onepoint-of-interest of the body; and (e) projecting said at least onepoint-of-interest on said at least one projection plane; such that, incourse of the procedure, the locations of the body and the imaginginstrument are known, thereby the at least one point-of-interest isprojectable on the at least one projection plane even in cases whereby arelative location of the body and the imaging instrument are changed.”

SUMMARY OF THE INVENTION

There is provided, in accordance with some embodiments of the presentdisclosure, a method of graphically presenting an indicating marker overa 3-D model of a tissue surface during a catheterization procedure usinga catheter probe, the method comprising: determining a region over the3-D model; deforming the indicating marker to obtain a deformedindicating marker that congruently matches a shape defined by the 3-Dmodel across the region at a plurality of positions; and rendering the3-D model into an image including the deformed indicating marker bygenerating an image of the 3-D model covered by the deformed indicatingmarker across the region defined by the plurality of positions.

In some embodiments, the indicating marker indicates a field of viewviewed from a location along the catheter probe, the location beingdetermined by a measured position and facing direction of a distal endof the catheter probe.

In some embodiments, an appearance of the indicating marker indicates arelative location of the catheter probe with respect to the tissuesurface, the relative location being determined based on a measuredposition and facing direction of a distal end of the catheter proberelative to the tissue surface.

In some embodiments, a size of the region indicates a distance betweenthe catheter probe and the tissue surface.

In some embodiments, a visibility of the indicating marker indicates adistance between the catheter probe and the tissue surface.

In some embodiments, an aspect ratio of the region indicates anorientation between the catheter probe and the tissue surface.

In some embodiments, the determining, the deforming and the renderingare performed iteratively for at least a portion of a duration of thecatheterization procedure.

In some embodiments, the presenting is updated at a frame rate of 10frames per second or more.

In some embodiments, the indicating marker indicates a planned path.

In some embodiments, the indicating marker points in a direction of aselected target site.

In some embodiments, the method further comprises identifying theindicating marker should be presented, the identifying is based on rulespre-associated with input expected to be acquired during thecatheterization procedure.

In some embodiments, the input comprises an identified onset of acatheter probe navigation process.

In some embodiments, the input comprises an identified onset of anablation.

There is provided, in accordance with some embodiments of the presentdisclosure, a method of graphically presenting a 3-D model of a tissueregion during a catheterization procedure, the method comprising:estimating an estimated effect of the catheterization procedure on thetissue region; calculating, based on the estimated effect, a shape, asize, and a position of a region to be marked on the 3-D model;selecting at least one material appearance property based on theestimated effect; and rendering the 3-D model to present the estimatedeffect using the assigned material appearance properties across theregion to be marked.

In some embodiments, the estimated effect comprises at least one of anestimated change in temperature, an estimated change in shape and anestimated change in size of the tissue region.

In some embodiments, the calculating a shape comprises calculating anarea of an ablation point.

In some embodiments, the calculating a shape comprises calculating adepth of an ablation point.

In some embodiments, the calculating a shape includes calculating a pathof a plurality of ablation points.

In some embodiments, the material appearance properties are selected tovisualize a state of the tissue.

In some embodiments, the material appearance properties comprise achange in at least one of the group consisting of reflectance,absorption, scattering, translucency, texture and any combinationthereof.

In some embodiments, the estimating comprises presenting the estimatedeffect as a function of time.

In some embodiments, the shape is recalculated as a function of time.

In some embodiments, the shape and the material appearance propertiesindicate an increasing spread of a lesioning effect.

There is provided, in accordance with some embodiments of the presentdisclosure, a method of visually rendering a 3-D model of a tissueregion to indicate a position and a facing direction of a catheter probeduring a catheterization procedure, the method comprising: determiningthe position and facing direction of a distal end of the catheter probewith respect to the tissue region; and rendering the 3-D model toinclude a simulation of a first indicating mark, the first indicatingmark being simulated in a position of a surface portion defined by the3-D model, wherein the position is also located along an axis extendingdistally from the determined position and in the determined facingdirection of the distal end of the catheter.

In some embodiments, the method further comprises rendering the 3-Dmodel to include a simulation of a second indicating mark, the secondindicating mark being simulated in a position of a second surfaceportion defined by the 3-D model, wherein second surface portionoccupies a closest surface position of the 3-D model to a predefinedportion of the distal end of the catheter.

In some embodiments, the first indicating mark and the second indicatingmark are rendered together as a single indicating mark when thedetermined position of the distal end indicates contact with a surfacedefined by the 3-D model.

In some embodiments, at least one of the indicating marks is shaped andpositioned to congruently match the corresponding 3-D model surfaceportion.

In some embodiments, the 3-D model is rendered as viewed from aviewpoint from outside an organ comprising the tissue region.

In some embodiments, the 3-D model is rendered as viewed from aviewpoint from within an organ comprising the tissue region.

In some embodiments, the tissue region comprises a body lumen.

In some embodiments, the 3-D model is rendered as viewed from aviewpoint offset to the distal end of the catheter probe.

In some embodiments, the determining and the rendering is providediteratively during at least a portion of the catheterization procedure.

In some embodiments, the method further comprises simultaneouslypresenting two or more views of the 3-D model, each viewed from adifferent viewpoint, the different viewpoints comprising a firstviewpoint being inside an organ comprising the tissue region and asecond viewpoint being outside the organ.

In some embodiments, both presentations include the first indicatingmark.

In some embodiments, at least one of indicating marks is simulated as anillumination of the 3-D model surface.

In some embodiments, the illumination is simulated to be uneven across asimulated illumination beam.

In some embodiments, a center of the illumination is calculatedaccording to a position and facing direction of the catheter proberelative to the tissue region.

In some embodiments, the center of illumination is graphically presentedby increased illumination intensity at a center of the beam.

In some embodiments, the method further comprises simulating a secondillumination source illuminating from a position distinct from theposition of the distal end of the catheter probe.

In some embodiments, the method further comprises simulating a secondillumination source, illuminating in a direction distinct from thefacing direction of the distal end of the catheter probe.

In some embodiments, the second illumination source is simulated as anambient light source.

In some embodiments, the rendering comprises selecting a materialappearance of a surface of the tissue region, the material appearance issimulated to be affected by the illumination.

In some embodiments, the rendering comprises rendering the tissue regionas at least partially translucent to the simulated illumination.

There is provided, in accordance with some embodiments of the presentdisclosure, a method of automatically modifying an image presenting a3-D model of a tissue region during a catheterization procedure, themethod comprising: associating each of a plurality of conditions with acorresponding image presenting the 3-D model; identifying an onset ofone condition of the plurality of conditions; automatically displayingthe image associated with the one condition in response to theidentifying of the onset of the one condition.

In some embodiments, the condition comprises a distance between a distalend of a catheter probe and a tissue surface shorter than a pre-setthreshold.

In some embodiments, the condition comprises the tissue surfaceincluding a target site.

In some embodiments, the condition comprises changing an operation stateof a catheter probe.

In some embodiments, the condition comprises detecting a contact of adistal end of a catheter probe with a surface of the tissue region.

In some embodiments, the image comprises a view of a cross-section of atissue depth.

In some embodiments, the image comprises a zoom in of the 3-D model.

In some embodiments, during the zoom in, an indicating marker isrendered across a region of the 3-D model.

In some embodiments, the image comprises a plurality of images of the3-D model, each viewed from a distinct viewpoint.

There is provided, in accordance with some embodiments of the presentdisclosure, a method of rendering a model of a tissue surface of aninside environment of an organ presented during a catheterizationprocedure using a catheter probe, comprising: receiving data indicativeof a position and a facing direction of a distal end of the catheterprobe with respect to the tissue surface; and rendering the model to animage having a viewing location within the organ, and distinct from anyposition along the catheter probe.

In some embodiments, the rendering further comprises generating agraphical presentation of at least a portion of the distal end of thecatheter probe.

In some embodiments, the distal end is presented at the position andfacing the facing direction.

In some embodiments, the location is further away from the tissuesurface than the distal end of the catheter probe.

In some embodiments, the method further comprises receiving anelectrical reading from an electrode mounted on the catheter probe, theelectrical reading indicating that a 3-D structure of the tissue surfacehas changed to a second structure.

In some embodiments, the method further comprises modifying the image topresent the second structure of the tissue surface.

There is provided, in accordance with some embodiments of the presentdisclosure, a system for graphically presenting an indicating markerduring a catheterization procedure, the system comprising computercircuitry configured to: receive a 3-D model of a body tissue region;determine a plurality of positions of the indicating marker relative tothe 3-D model; and present an image of at least a portion of the 3-Dmodel partially covered by the indicating marker deformed to congruentlymatch the 3-D model at the determined position.

In some embodiments, the circuitry is configured to deform theindicating marker using a graphical game engine.

In some embodiments, the system further is configured to sense dataindicative of a position and facing direction of a distal end of acatheter probe.

In some embodiments, the circuitry is configured to determine theplurality of positions according to the position and facing direction ofthe distal end of the catheter probe.

In some embodiments, the system comprises a display configured todisplay the presented image.

In some embodiments, the computer circuitry is configured to produce the3-D model.

In some embodiments, the 3-D model is produced using data obtained froman intra-body probe.

In some embodiments, the 3-D model is produced using image data.

In some embodiments, the computer circuitry is configured to present theimage with indications of use made of the treatment element during thecatheterization procedure.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention pertains. Although methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, exemplarymethods and/or materials are described below. In case of conflict, thepatent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and are notintended to be necessarily limiting.

Implementation of the method and/or system of embodiments of theinvention can involve performing or completing selected tasks manually,automatically, or a combination thereof. Moreover, according to actualinstrumentation and equipment of embodiments of the method and/or systemof the invention, several selected tasks could be implemented byhardware, by software or by firmware or by a combination thereof usingan operating system.

For example, hardware for performing selected tasks according toembodiments of the invention could be implemented as a chip or acircuit. As software, selected tasks according to embodiments of theinvention could be implemented as a plurality of software instructionsbeing executed by a computer using any suitable operating system. In anexemplary embodiment of the invention, one or more tasks according toexemplary embodiments of method and/or system as described herein areperformed by a data processor, such as a computing platform forexecuting a plurality of instructions. Optionally, the data processorincludes a volatile memory for storing instructions and/or data and/or anon-volatile storage, for example, a magnetic hard-disk and/or removablemedia, for storing instructions and/or data. Optionally, a networkconnection is provided as well. A display and/or a user input devicesuch as a keyboard or mouse are optionally provided as well.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, it is stressed that theparticulars shown are by way of example and for purposes of illustrativediscussion of embodiments of the invention. In this regard, thedescription taken with the drawings makes apparent to those skilled inthe art how embodiments of the invention may be practiced.

In the drawings:

FIGS. 1A-1E are flow charts illustrating exemplary processes forrendering and modifying the visual presentation of a tissue model asdescribed herein, in accordance with some embodiments of the invention,wherein FIG. 1A exemplifies a process for rendering a simulatedindicating marker over a 3-D tissue model, FIG. 1B exemplifies a processfor rendering a geometric tissue model based on estimated data, FIG. 1Cexemplifies a process for providing a point of reference for a catheterby rendering a 3-D tissue model, FIG. 1D exemplifies a process forautomatically modifying the image used to present a 3-D tissue model andFIG. 1E exemplifies a viewpoint used to render a 3-D model;

FIG. 2 is a flow chart illustrating an exemplary medical process whichmay benefit from using the visual rendering and display as describedherein, in accordance with some embodiments of the invention;

FIGS. 3A-3D show the 3-D model as rendered from two exemplary viewpoint,together with a simulation of an illumination, in accordance with someembodiments of the invention, wherein FIG. 3A illustrates a shooter'sview of the catheter facing a vein, FIG. 3B illustrates an out-of-organview of the catheter position in FIG. 3A, FIG. 3C illustrates ashooter's view of the catheter facing an inner wall of the heart andFIG. 3D illustrates an out-of-organ view of the catheter position inFIG. 3C;

FIGS. 4A-4B show a simulation of the flashlight feature, in accordancewith some embodiments of the invention, wherein FIG. 4A illustrates ashooter's view and FIG. 4B illustrates an out-of-organ view;

FIGS. 5A-5D show a simulation of a shape-specific indicating markerfeature, in accordance with some embodiments of the invention, whereinFIG. 5A illustrates a projection over a first surface, FIG. 5Billustrates a projection over a second surface, FIG. 5C illustrates aprojection over a third surface, FIG. 5D illustrates a projection over aforth surface;

FIGS. 5E-5G illustrate various schematic deformations and congruentmatching of an indicating marker to a surface;

FIGS. 6A-6F show a simulation of identifying a target and starting anablation, in accordance with some embodiments of the invention, whereinFIG. 6A shows a left atrium inner view, FIG. 6B shows left superior andinferior pulmonary veins, FIG. 6C exemplifies an identification of aplanned ablation path, FIG. 6D exemplifies the appearance of detailssuch as planned ablation sub-regions, FIG. 6E exemplifies directing acatheter towards a sub-region and FIG. 6F exemplifies shifting in pointsof view during an ablation process;

FIGS. 7A-7F exemplify a point of view of an ablation of a sub-region, inaccordance with some embodiments of the invention, wherein FIG. 7Aexemplifies a catheter approaching the targeted sub-region, FIG. 7Bexemplifies the surface of the sub-region being pushed by the contactforce of the catheter, FIG. 7C exemplifies tissue surface getting warm,FIG. 7D exemplifies a tissue depth getting warm, FIG. 7E exemplifies atissue getting scarred and FIG. 7F exemplifies a catheter beingwithdrawn from the treated sub-region;

FIG. 8 exemplifies an ablation area overview simulation, in accordancewith some embodiments of the invention; and

FIGS. 9A-9G exemplify a sub-region elimination of a ganglion, whereinFIGS. 9A-9D exemplify a single sub-region ablation simulation showingganglia ablation as an example, and FIGS. 9E-9G exemplify ganglionelimination by injecting an eliminating substance, in accordance withsome embodiments of the invention, wherein FIG. 9A exemplifiesidentifying the target, FIG. 9B exemplifies contacting the target, FIG.9C exemplifies tissue heating and FIG. 9D exemplifies scar formation andwherein FIG. 9E exemplifies injector penetration into the target, FIG.9F exemplifies initial injection stage and FIG. 9G exemplifies advancedinjection stage;

FIGS. 10A-10B exemplify validation processes, in accordance with someembodiments of the invention, wherein FIG. 10A exemplifies a simulationof a validation procedure, and FIG. 10B exemplifies an overview of a premade plan when compared to the actual procedure;

FIG. 11 schematically represents software components and data structurescomprised in and/or used by an interaction analyzer of a display system,according to some embodiments of the present disclosure;

FIG. 12 schematically represents components, inputs, and outputs of agraphical game engine operating to manage and render scene elements tomotion frame-rate images, according to some embodiments of the presentdisclosure; and

FIG. 13 is a schematic representation of a display system configured fordisplay of interactions between a catheter probe and a body tissueregion, and/or their effects, according to some embodiments of thepresent disclosure;

FIG. 14A is a flow chart schematically describing a cardiac ablationprocedure, wherein indicating marks are placed on a 3-D model which isdeveloped from data obtained during the procedure itself, according tosome embodiments of the present disclosure;

FIGS. 14B-14E show a phase of iterative intra-procedure reconstructionof a model of a right atrium and connecting blood vessels including thesuperior vena cava and inferior vena cava, according to some embodimentsof the present disclosure; and

FIG. 15 illustrates use of indicating marks for showing a currentposition of a tip of a probe positioned within a 3-D model of a bodylumen, according to some embodiments of the present disclosure.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to systemsand/or methods for assisting a surgeon in catheterization procedures,more particularly, but not exclusively, to such system and/or methodsthat make use of dynamic visual representations.

Overview

An aspect of some embodiments of the invention relates to a userinterface for assisting in medical procedures, guiding a surgeon byupdating the appearance and/or images used to render a 3-D model of atissue, optionally based on a catheter probe's position and/or operationwith respect to the modeled tissue.

In some embodiments, a user interface is configured to display anindicating marker deformed to match a 3-D model of a tissue surface,optionally during a catheterization process. In some embodiments, theindicating marker marks a portion of the field of view viewed from alocation along a catheter probe. Optionally, a graphical object isassigned to the indicating marker. For example, a marker for marking anablation site may be assigned a graphical object with defined visualappearance properties, such as shape, color, texture, etc. In someembodiments, the graphical object is rendered across a region of the 3-Dmodel, the object being deformed to congruently match the 3-D geometricsurface of the model. In some embodiments, congruent matching comprisesdeforming the graphical object to match the 3-D model at a plurality ofpositions across a determined region to be marked.

As used herein, the term indicating marker is any graphical objectincluded in an image, for use as a visual indicator of measured and/orcalculated and/or estimated data. For example, an indicating marker maybe an icon indicative of a measured position and/or orientation of acatheter probe. In another example, an indicating marker may be amarking representative of calculated heat dissipation based on ablationparameters. In yet another example, an indicating marker may be anindicative visual sign (e.g., an icon) indicative of an estimated effectof an ablation procedure, such as estimated scarring.

In some embodiments, a graphical object comprises an icon, and/or asymbol, and/or a character, and/or a picture, and/or sign, and/or visualindicator, and/or a marker. Optionally, an indicating marker includes adelimitation of a region across the 3-D model. In some embodiments, the3-D model is rendered across the delimited region to visually representa modified appearance. Alternatively or additionally, the indicatingmarker is congruently matched to the 3-D shape of the model, resultingin a patient-specific marker.

The term simulation and its inflections (e.g., simulated, simulating,etc.) refers herein to imitation of the operation of a tissue or organof a patient during a catheterization procedure. The act of simulatingthe tissue or organ is based on a model. The model may include astructural model (e.g., a 3-D anatomical model) and a functional model.The functional model may supply rules for the changes occurring in the3-D anatomical model over time under conventional conditions, and underthe conditions that may evolve during the procedure. The simulation maybe represented by a motion frame-rate, real-time display, showinggraphical images that change over time in manners indicative to thechanges that the tissue or organ undergo at the time of display. Thedisplay and/or conditions that evolve during the catheterization processmay be recorded to allow replaying the simulation also off-line, e.g.,after the procedure is over, for example, for studying how to runsimilar procedures to gain similar or better results.

In some embodiments, the modeled tissue is an inner environment of anorgan of a patient, possibly a lumen. In some embodiments, the organ isa heart and optionally the lumen is a vein and/or artery of the heart.Alternatively or additionally, the lumen is an atrium and/or aventricle. Alternatively or additionally, the modeled tissue comprisesan outer form of a patient's organ. In some embodiments, a 3-D model isobtained based on imaging data acquired from the patient, for example,such as imaging acquired by magnetic resonance imaging (MRI), and/orcomputed tomography (CT), and/or by ultrasound (US) and/or by nuclearmedicine (NM). Alternatively or additionally, data is acquired bymeasuring thermal and/or dielectric tissue properties. Optionally, aninitial 3-D model of the tissue is provided by presenting a mesh of aplurality of data inputs. In some embodiments, the catheterizationprocedure includes navigation of the catheter probe inside the patient'sbody and/or organ. Alternatively or additionally, the catheterizationprocedure includes an ablation process. Alternatively or additionally,the catheterization procedure includes planning (optionally,preplanning; that is, planning in advance of catheterization itself) ofan ablation process.

In some embodiments, rendering the 3-D model into an image including thedeformed indicating marker is provided by generating an image of the 3-Dmodel covered by the deformed indicating marker across the regiondefined by the determined plurality of positions. In some embodiments,generating an image covered by the indicating marker includes blendingin the indicating marker with the rendered image of the 3-D model.Alternatively or additionally, generating an image covered by theindicating marker includes rendering the indicating marker just below asurface of the modeled tissue, shown by rendering the surface at leastpartially transparent.

In some embodiments, the viewpoint used to render the 3-D model isoffset to the viewpoint indicated by the indicating marker. For example,when the indicating marker signifies a viewpoint located along thecatheter probe, the viewpoint used to render the 3-D model may be offsetto the location of the catheter probe, as if viewed by a “third person”.Optionally, the field of view of the “third person” can include both theindicating marker and at least a portion of the distal end of thecatheter probe, i.e. the end inside a region of the patient comprisingone or more target sites.

In some embodiments, the region used to render the indicating markeracross the 3-D model is at least partially determined based on datainputs from one or more measurement sources active during thecatheterization procedure. In some embodiments, the rendered region isbased on a simulated projection of the graphical object onto the modeledtissue surface from a viewpoint location. Optionally, the viewpointlocation is determined as being offset to a measured and/or estimatedand/or calculated position and/or facing direction (for example, adistal direction along a longitudinal axis of a distal portion of theprobe) and/or orientation of a catheter probe. Optionally, the viewpointlocation is determined to be further away from a distal end of thecatheter, with respect to the tissue it is facing.

Optionally, a position and/or facing direction and/or orientation of thecatheter probe are determined relative to the modeled tissue.Alternatively or additionally, a stationary environment, such as a roomand/or a procedure venue, is used to determine the position and/orfacing direction and/or orientation of the catheter probe. Optionally,position and/or facing direction and/or orientation of the distal end ofthe catheter probe are determined.

In some embodiments, the appearance of the graphical object isindicative to the spatial relations between the catheter probe and thetissue surface. Optionally, the appearance includes size, and/or aspectratio, and/or visibility, and/or color and/or transparency and/orreflectance. In some embodiments, spatial relations are expressed bydistance, and/or relative tilting angle.

In some embodiments, the appearance of the graphical object may dependon the location and/or orientation of the catheter probe in respect tothe tissue surface, so that a surgeon may infer the location and/ororientation from the appearance of the graphical object. For example, insome embodiments the size of the region to be marked is indicative to ameasured and/or estimated distance between the catheter probe,optionally its distal end, and the tissue surface.

For example, a shorter distance may be indicated by a larger region sizeand/or a larger distance may be indicated by a smaller region size. Apotential advantage of a region size being anti-correlated to thedistance is that a shorter distance is usually intuitively perceived byobjects seeming larger than when viewed from a larger distance.Alternatively or additionally, the shape of the region is indicative ofthe relative orientation of the probe to the tissue surface. Optionally,the relative orientation of the catheter probe to the tissue surface isdefined by the angle between the facing direction of the catheter andthe mean direction of the tissue surface it is facing. In someembodiments, a stretching degree of the graphical object is indicativeof the relative orientation. For example, a non-stretched graphicalobject (e.g., of aspect ratio of about 1) may be indicative ofperpendicularity between the probe and the tissue surface, whilestretched graphical object may be indicative to the catheter probe beingsubstantially parallel to the wall, for example, when the catheterextends along a lumen.

In some embodiments, the visibility of the graphical object correspondsto the position and/or facing direction of the catheter probe. In someembodiments, visibility relates to the intensity level and/or contrastand/or sharpness of the presented graphical object. For example, whenthe graphical object is simulated to be projected on a tissue wall, theintensity level of the visibility of the graphical object may correspondto the distance between the tissue wall and the catheter probe,optionally, determined by a distance between the mean surface of thetissue wall and the distal end of the catheter probe.

Optionally, determining the region to be marked, the deformation of thegraphical object across that region and the rendering of the model inthat region are provided iteratively during at least a portion of theduration of the catheterization procedure. For example, the appearanceand/or size of the graphical object may change during the procedureaccording to changes in the spatial relationship between the catheterprobe and the tissue surface.

In another example, real-time measurements of heat dissipationthroughout the tissue may modify the size and/or shape of the region tobe marked, and accordingly the deformation of the graphical objectacross the modified region. Alternatively, heat dissipation is estimatedrather than measured. In some embodiments, determining the region to bemarked, the deformation of the graphical object across that region andthe rendering of the model in that region are presented as a function oftime, according to estimated effects. For example, once an ablation hasbeen performed, an effect of tissue heating, followed by tissue coolingand/or scaring is estimated, and this estimated effect may be presentedas a function of time from the onset and/or completion of the ablation.

Alternatively or additionally, during the procedure it is identifiedthat an indicating marker should be presented, possibly by identifyingpre-set rules. For example, some indicating markers may be pre-set toappear only during navigation inside the heart, so when the catheterprobe enters the heart it may be identified that such an indicatingmarker is to be presented, and when the catheter probe exits from theheart, such an indicating marker disappears. For example, in someembodiments, the indicating marker may be pre-associated with detectingan onset of a navigation process of the catheter probe, and may bepresented to the surgeon only during detected navigation.

In some embodiments, rules that identify that a certain indicatingmarker is to be presented are pre-associated with input expected to beacquired during the catheterization procedure, for example, inputindicative of the catheter being navigated, approaching a wall, ablatingtissue, etc. In some embodiments, the input pre-associated with thepresentation of an indicating marker is dynamically acquired during thecatheterization procedure, so that, for example, when navigation ends, amarker that is to be presented only during navigation will disappear. Insome embodiments, rules are limited to be associated with positionand/or facing direction and/or operation status of a catheter probe.

In some embodiments, input pre-associated with presenting the indicatingmarker comprises an onset of an ablation. Optionally, detecting anablation onset may be associated with presenting a graphical object,and/or with removing the visual presentation of the graphical object. Insome embodiments, ablation sites are marked based on planned data oftarget sites, optionally by visually representing a planned ablationpath and/or ablation marks. In some embodiments, when detecting anablation onset, and/or when identifying navigation in proximity to anablation target site, at least one graphical object is rendered across aregion in the 3-D model.

Optionally, a plurality of graphical objects represent ablation sites.

An aspect of several embodiments of the invention relates to renderingan appearance of a 3-D model based on an estimated effect of acatheterization procedure. In some embodiments, an estimated effect mayinclude, for example, tissue heating, cooling, and/or swelling; and/orthe degree of tissue heating and/or tissue cooling and/or tissueswelling. In some embodiments, a region to be marked on the 3-D model isdetermined based on the estimated effect, optionally, by estimating ashape, and/or a size and/or a position of the effect across the 3-Dmodel.

In some embodiments, the estimated effect-adjusted appearance of the 3-Dmodel is rendered only in a region to be marked. Optionally, renderingan appearance of the 3-D model comprises selecting at least one materialappearance property (MAP), optionally from a database. In someembodiments, rendering the appearance includes rendering for visualdisplay an image of the 3-D surface defined by the 3-D model. Apotential advantage of manipulating the appearance of the surface of the3-D model is a quicker-to-understand, more intuitive and/or more easilyinterpreted presentation of the presented data, as compared, forexample, to tagging using icons which do not conform to the modeledshape. Close into a display used by an operator to guide an intrabodyprobe, and/or to improve the accuracy and/or precision with whichactions by and/or through the probe (e.g., contacts and/or treatmentadministration) are associated to positions on the heart wall.

There is also a potential for reduction of error and/or ambiguity,and/or increase in accuracy in navigating of an intra-body probe withrespect to a target indicated by a surface-conforming mark (for example,a mark which is implemented by changing the appearance of the surface ofa portion of the 3-D model). Insofar as the surface mark and the surfacestate indications are rendered onto the same surface (e.g., rather thanone floating above or otherwise ambiguously related to the other), it ispotentially possible to make fine distinctions as to the need for anadjustment, and/or the adjustment to be made: e.g., to judge and/orselect more precisely a degree of overlap between adjacent existing,planned, and/or selected lesion sites.

Optionally, a corrective action in a movement or a plan adjustsinteractions with marked tissue surfaces, based on the appearance of themark. For example, upon approaching a mark, the operator of theintra-body probe can adapt navigating actions to account for theorientation of the surface. More particularly, a fixed-size mark (forexample, a fixed-size mark indicating an intersection of an axisextending along the probe's current orientation with a modeled 3-Dsurface), may look compressed along one axis if the modeled 3-D surfaceis not orthogonal to a viewing axis (e.g., from the point of view of theprobe). Additionally or alternatively, a searchlight-like mark (e.g.,rendered to simulate a fixed-angle beam emitted from a probe's distalend and along its longitudinal axis) will appear non-circular on thesurface from viewpoints at angles away from the longitudinal axis, whenthe probe is not orthogonal to the surface. Orthogonal contact (forexample) may be preferable for some procedures such as injection and/orablation, to help control results; and a non-preferred angle of approachcan be corrected during a procedure once recognized. In another example,a shape of a surface-conforming mark may indicate to a user that themark lies across a surface region having an irregular shape, such as aridge of tissue (which may otherwise be sufficiently low-contrast inappearance that the shape irregularity is hidden or unclear). The useroptionally adjusts a procedure (for example, moves a planned ablationlocation) in order to avoid the surface region with the irregular shape.In some embodiments, knowledge of a shape of a region targeted for aprocedure is optionally updated during the procedure itself. Knowledgeof other properties such as tissue state may also be updated during aprocedure based on measurements; for example, state of tissue health,state of tissue edema, and/or state of tissue capacity to propagateelectrical impulses. Insofar as marks are applied to the surface of theshape itself, an operator is able to make corrections to a plannedprocedure as it becomes apparent that marks indicating the plan aredirectly associated with revised-shape and/or revised-state surfaceregions that are potentially problematic.

In some embodiments, an estimated effect comprises an estimated changein temperature, such as for example, estimating heating when ablatingand/or estimating cooling after ablation. Alternatively or additionally,an estimated effect comprises an estimated change in shape, for example,after ablation it might be estimated that a tissue will become swollen.

Alternatively or additionally, an estimated effect comprises anestimated change in texture, for example, when estimating the formationof a scar tissue, optionally resulting in variation of surface texture.Alternatively or additionally, an estimated effect comprises anestimated change in size, such as for example, following a measuredand/or estimated edema, which may be estimated to take place followingan ablation.

Optionally, the shape and/or appearance of a delimited region of the 3-Dmodel is calculated based on the estimated effect. For example, bordersof a region estimated to be heated as a result of ablation may becalculated based on an electrical power fed to an ablating element inthe probe, the type of the ablated tissue, the tissue properties and soforth.

In some embodiments, an extent of a region to be rendered is calculatedbased on the estimated effect, such as by estimating an effect of aprobe contact size, for example when estimating an area and/or a depthof ablation at a given ablation location. In some embodiments, theextent of the rendered region comprises a path of a plurality ofablation locations, optionally, some of which represent locations whichwere already ablated and some of which represent targets for ablation.

In some embodiments, a motion frame-rate, real-time display of achanging shape of tissue model is provided, wherein material appearanceproperties of the 3-D model are changed based on estimations resultingfrom ongoing measurements of interactions between a catheter probe andthe actual tissue being modeled. Potentially, visually representingestimated data by changing the material appearance of a tissue's 3-Dmodel may provide more realistic graphical presentation. In someembodiments, the realistic graphical presentation is selected to providea more intuitively understandable presentation than that achievable withpresentations that are not realistic. Optionally, appearances of sceneobjects are “realistic” in one or more aspects, for example, tissues areprovided with material appearances that mimic their appearance in lifeand/or reactive behaviors (e.g. in response to injury, treatment,contact, and/or pressure). Optionally, scene object are given behaviorswhich are “naturalistic” as the term is used herein, with the resultthat they are not convincingly realistic, but nevertheless look and/orbehave consistent with the possession of a virtual “substance”.

Some embodiments involve visual rendering of surfaces and/or volumes ascomprising virtual material. A virtual material, in some embodiments, isa material subject to simulated optical rules approximating processessuch as reflection, scattering, transparency, shading, and lighting. Notevery optical rule used in virtual visual rendering is a copy of areal-world rule; the art of computer rendering includes numeroustechniques (for achieving both realistic and deliberately unrealisticresults) which apply optical rules that have no direct physicalequivalent. For example, bump mapping simulates surface heightirregularities by manipulation of reflectance.

A region can be rendered statically or dynamically. In some embodiments,the region is rendered dynamically, and the changed material appearanceover time is based on real-time input data, i.e. data collected during aprocedure. For example, upon detection of a catheter ablation onset, asimulation of the tissue being heated is provided, and the 3-D model ofthe tissue is rendered so its appearance is affected by data collectedduring the ablation process. As used herein, real-time refers to themotion frame-rate, real-time display of a changing simulated tissue.

For example, a region can be rendered dynamically when a catheter isidentified as approaching a tissue beyond a distance threshold, and theappearance of the tissue model is set to be indicative to the state ofthe tissue, such as hydration level, and/or edema, and/or fibrosis.Optionally, the tissue state is indicated by selecting a materialappearance corresponding to at least one property of that state. In someembodiments, the tissue state is indicated by changing the materialappearance of the geometrical surface and/or depth of the tissue basedon ongoing measurement of tissue properties.

In some embodiments, a software environment specialized for interactivevisual simulations (for example a 3-D graphical game engine such as theUnreal® or Unity® graphical game engines) is used as a basis forimplementing the tissue simulation. For visual rendering by the gameengine graphics pipeline, material appearances of tissue are optionallycontrolled by one or more material appearance properties (preferably aplurality of such properties). In some embodiments, material appearancesare rendered according to how materials interact with simulated opticaland lighting conditions.

In some embodiments, rendering material appearance properties is based,wholly or partially, on pre-stored input data. The pre-stored input datamay relate to a plan for the catheterization procedure, and may include,for example, a planned ablation path. The path may be characterized byposition and size. Alternatively or additionally, rendering materialappearance properties is at least partially based on input data receivedon-line during the procedure, e.g., from one or more data sources activeduring a procedure in real-time. In some embodiments of the presentinvention, the data inputs optionally include inputs related to theperformance of a catheter procedure—for example, catheter probe positiondata, data tracking the operation state of the catheter, and/ormeasurement data, for example measurement data obtained from anintrabody probe.

Optionally, material appearance properties are based directly onmeasured data, for example, material appearance of a modeled tissue maychange as the tissue is being heated. The change in material appearanceproperties may be in accordance with real-time thermal measurements ofthe tissue. Alternatively or additionally, material appearanceproperties are based on estimated data derived from the measured data.For example, once an ablation is conducted, it is estimated that thetissue is being heated, and the extent of the heating can be derivedfrom measured data of the probe or the tissue.

In some embodiments, material appearance properties are presented toillustrate a realistic representation of the tissue, as provided byinput collected in real-time. Alternatively or additionally, materialappearance properties are based on what is referred to herein as“naturalistic” representation, optionally based on exaggeration ofmeasured and/or calculated data, for example, by exaggerated stretchingand/or swelling of the appearance of a tissue based on a water retentionstatus of the tissue. Herein, “naturalistic” appearance means that thedisplayed result gives an operator the impression of substantial(volume-occupying, as opposed to merely shell defining) and/or reactivematerials existing in a fluidly navigable environment. The reactions ofthe materials in turn become a significant part of the information whichan operator relies on to act within the actual environment that thescene simulates. A material moreover may be simulated as occupyingvolume per se (for example, as a wall having thickness), rather thanmerely as a boundary extending in space (for example, as a structuredefining a surface, but having no well-defined thickness).

In some embodiments, in addition or as an alternative to immediateeffects of probe-tissue interaction, longer-term effects are optionallysimulated and displayed. The longer-term effects are optionallyestimated; for example, a simulation that converts estimated lesiondamage into parameters for a script describing the gradual onset oftissue edema.

An aspect of some embodiments of the invention relates to automaticallymodifying, during a catheterization procedure, an image presenting amodeled tissue.

Optionally, modifying an image comprises modifying the viewpoint used torender the modeled tissue, for example, a viewpoint from within theorgan comprising the tissue region being modeled and/or a viewpoint fromoutside the organ. Alternatively or additionally, modifying an imagecomprises switching between a single representation of the model to aplurality of representations of the model, or vice versa. An example ofa plurality of representations of a model includes simultaneouslypresenting more than one image, for example different images presentingdifferent viewpoints. Alternatively or additionally, modifying an imagecomprises zooming in or zooming out from the rendered field of view.Alternatively or additionally, modifying an image comprises switchingbetween a front view of the modeled tissue to a cross-sectional view ofthe modeled tissue, and vice versa. In some embodiments, an image isautomatically generated during the catheterization process in accordancewith an identified condition

In some embodiments, each of a plurality of conditions is associatedwith an image presenting the 3-D model. Optionally, the conditions arerelated to the catheterization process, including for example, therelative position and/or orientation of the catheter probe relative tothe presented tissue region, or for example an onset of an ablationprocess.

In some embodiments, the condition is related to a catheter's positionand/or action with respect to the modeled tissue. Optionally, anassociated condition comprises a distance between a distal end of acatheter probe and a tissue surface shorter than a pre-set threshold. Insome embodiments, a different pre-set threshold value is set fordifferent tissues, for example, when a distal end of the catheterapproaches a tissue surface, the view may be zoomed in. The thresholdfor zooming in may differ based on the existence of planned sites on thetissue surface. For example, if the tissue surface includes a plannedsite (e.g., a planned ablation site), zooming-in may take place at alarger distance than if the tissue does not include planned sites.

In some embodiments, when approaching a tissue, optionally beyond apre-set threshold, an indicating marker is rendered over the 3-D model.For example, when approaching a tissue having a planned ablation site,marking of the planned ablation site may appear when the catheter probeis detected to cross over a pre-set distance threshold.

An aspect of some embodiments relates to a simulated illuminationrendered across a 3-D model during a catheterization procedure, shown byupdating a presentation of the 3-D model to appear as if light is beingprojected over it. In some embodiments, the illumination is simulated tobe originating from a determined position and/or illuminating in adirection of a determined facing direction of a distal end of a catheterprobe. Optionally, projected light properties, such as intensity and/ordispersion, correspond to the determined probe position and/ororientation with respect to the tissue.

In some embodiments, the model is rendered from a viewpoint defined by alocation over the catheter probe and by the facing direction of theprobe. Alternatively or additionally, the model is rendered from aviewpoint location being distinct from the catheter probe, optionallyincluding the distal end location of the catheter. Alternatively oradditionally, the model is rendered from a viewpoint location beingoutside the organ comprising the catheter probe, optionally visuallypresenting only the illumination simulated to originate from the probe.

In some embodiments, the simulated illumination is rendered as iforiginating from a flashlight positioned in proximity to the distalportion of the probe and facing the modeled tissue. In some embodiments,a point-of-view of looking from the outside of the organ and seeing theflashlight as if illuminating from within the organ is provided. In thisembodiment, the tissue of the organ is rendered to be transparent enoughto let light pass through it.

An aspect of some embodiments of the invention relates to a presenting amodel of a tissue surface as viewed from a location over a catheterprobe, optionally during a catheterization procedure. In someembodiments, the model is rendered to be viewed from a viewpointlocation being further away from the tissue surface than the distal endof the catheter probe. Optionally, the relative distance and/or facingdirection between the tissue surface and the catheter probe isdetermined by receiving data indicative of a position and a facingdirection of the distal end of the catheter probe with respect to thetissue surface.

In some embodiments, a graphical representation of at least a portion ofthe distal end of the catheter probe is rendered over the image,optionally correlating to the real edge distance of the catheter probe'sdistal end from the viewpoint location used for the rendering the 3-Dmodel. In some embodiments, the presented catheter's distal end isdynamically presented, optionally rendered to be oriented with thedetected position and/or facing direction. In some embodiments,rendering of the tissue model is provided in real-time, i.e. duringacquiring of input, such as for example, electrical reading optionallyfrom an electrode mounted on the catheter probe. In some embodiments,the input detects that the 3-D structure of the tissue model has changedto a second structure. Optionally, the model is rendered to present thesecond structure of the tissue surface.

Aspects of some embodiments of the invention are described in thefollowing exemplary embodiments, depicting an exemplary cardiac ablationprocedure. It should be noted, however, that various aspects andimplications of the invention which are described in the context ofablation and/or cardiac embodiments, are probably applicable to manyother medical procedures, and/or other patient anatomies, and theembodiments of the invention as described herein are not limited in anyway to the illustrative example of cardiac ablation.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not necessarily limited in itsapplication to the details of construction and the arrangement of thecomponents and/or methods set forth in the following description and/orillustrated in the drawings. The invention is capable of otherembodiments or of being practiced or carried out in various ways.

Exemplary Ablation Procedure

Aspects of some embodiments of the invention relates to a user interfacefor assisting in medical procedures, guiding a surgeon by updating theappearance and/or images used to render a 3-D model of a tissue,optionally based on a catheter's position and/or operation with respectto the modeled tissue. In some embodiments, catheterization proceduresare directed for treating cardiac arrhythmia conditions, such as forexample atrial fibrillation (AF) and/or atrial flutter (Afl) and/orsupraventricular tachycardia (SVT) and/or atrial tachycardia and/orMultifocal Atrial Tachycardia (MAT). Alternatively or additionally, aprocedure is directed to cancer treatments, and/or pain management,and/or for cosmetics purposes.

Referring now to the drawings, FIG. 2 shows a flowchart depicting anexemplary high level outline of a cardiac ablation procedure, such asfor example for treating AF, while executing embodiments provided by thecurrent invention.

Optionally, a patient, such as for example, a patient suffering from acardiac arrhythmia condition, is selected for treatment 202, such as forexample, ablation and/or neuromodulation. In some embodiments, a patientis imaged 204 to obtain a shape of an organ or part thereof; for exampleto obtain a cardiac tissue 3-D shape. As used herein, a tissue includesat least a portion of a patient's organ. In some embodiments, imaging isdone by magnetic resonance imaging (MRI), and/or computed tomography(CT), and/or by ultrasound (US) and/or by nuclear medicine (NM).Alternatively or additionally, data is acquired by measuring thermaland/or dielectric tissue properties. In some embodiments, data acquiredby sensing dielectric properties is used in obtaining the shape of theorgan, in addition to or instead of data from the imaging of block 204.Optionally, an initial 3-D geometric tissue model is provided bycombining a mesh of a plurality of data inputs, e.g., from differentimaging modalities. Optionally, such data is used in a diagnosis processof the patient 206.

Preplanning and Plan Adjustment

Based on the pre-acquired data, in some embodiments, a surgeon and/or asimulation program preplans an operation procedure 208. The operationprocedure may include, for example, generating a lesion. In someembodiments, a preliminary target to be lesioned is visually presentedto a surgeon, e.g., as a path (for example a continuous path, and/or apath described as a series of locations to be lesioned). In the visualrepresentation, the path may be presented as matched to a 3-D model ofthe patient's tissue.

For example, during a preplanning phase a surgeon may draw a pathcreating a 2D structure over a presented 3-D model. In some embodiments,the path is then deformed to match across a region of the 3-D model ofthe patient-specific anatomy, thereby leading to a planned graphicalstructure which is specific to the patient at hand.

Optionally, the preplanning comprises planning a line of ablationpoints, along which lesions are to be formed. The line may include aplurality of locations at which ablation is to be performed to createsub-lesions. Optionally, planned ablation locations are shown as areamarkings. In some embodiments, planned lesion area markings size takesinto consideration the ablation tool being used.

In some embodiments, the size of the lesion area marking corresponds tothe contact area of the ablation tool; indicating, for example, that aprobe with a specific surface contact area will be used. Optionally, anindicating marker is also used in illustrating the order of ablations,and in some embodiments the order of ablations is represented visually,for example by using a gradient of a visual parameter, such as whencolor intensity of area markings goes down or up in accordance withtheir planned ablation order.

In some embodiments, an ablation plan includes specification of whereablation is to occur; optionally defined as a line or path, an area,and/or a volume (herein, ablation plans for a path are provided asexamples, without limiting away from embodiments using areal orvolumetric specifications). A visual presentation of an ablation planwhich may be displayed to a surgeon during the procedure, optionallyfurther comprises a presentation of ablation parameters (for example,total energy to be delivered, power and/or timing).

In some embodiments, graphical presentation of the planned procedure,being matched with a patient-specific shape, is provided to a surgeonduring the procedure in real-time. In some embodiments, the graphicalpresentation is dynamic. For example, If the procedure in real-timedeviates from the planned procedure (e.g., due to changes in followingthe plan, differences in plan effects from those anticipated,differences in actuality of the state of the patient and/or proceduresite from the state anticipated in the original plan, and/or realizationof a benefit for following an alternative plan), the graphicalpresentation dynamically changes accordingly. For example, an indicatingmarker can change according to real-time measurements, such as real-timedielectric measurements and/or real-time thermal input.

Navigating and Dynamic Image Modification

In some embodiments, a procedure starts when a catheter probe isinserted into the patient 210, and optionally used for navigating 212and/or for identifying a target 214.

Optionally, the user interface graphically represents aspects related tomaneuvering within the confines of an anatomical space, the graphicsbeing presented as material appearance of the 3-D model. For example,there may be mechanical limitations on the maneuvering of an ablationcatheter which in some embodiments are graphically represented in thegeometrical model by shading the surface area and/or modifying thegeometrical surface of the area to seem dim and/or dull and/or otherwisemake it appear to be unreachable.

In another example, an anatomical region which is mechanicallyaccessible could be inappropriate for lesioning. Such anatomical regionsmay be graphically presented as unreachable, or in any other waydesigned to deter the surgeon from lesioning them. Anatomical regionsthat are not to be ablated may include, for example, a region of theesophagus and/or arteries and/or venous roots and/or autonomic gangliaand/or phrenic nerve.

In some embodiments, at least one measured and/or estimated tissueproperty is updated during navigation 212. The update may be by changingmaterial appearance properties of the presented 3-D model. For example,an aspect of several embodiments of the invention relates to updating atissue model according to a hydration state of a patient, in real-time.In some embodiments, graphical simulation is used to graphicallyrepresent a hydration state of a patient. In some embodiments, asimulation of exposure to an optical light environment is used tographically present a wet appearance to a tissue model, optionallycorrelated with a hydration measurement state.

In some embodiments, a color used to render a 3-D model of a tissuesurface is determined by the presence of at least one biological marker.For example, red color can in some embodiments represent levels ofhemoglobin protein. Alternatively or additionally, color is determinedaccording to a surface characteristic, for example, color changeaccording to a roughness level of a surface tissue. For example,roughness may represent rough texture features of a tissue such asfibrosis.

In some embodiments, presentation is refreshed at a rate of tens oftimes per second. A potential advantage of a relatively fast refreshrate is showing real-time state of the tissue even when the catheterinteracts with the tissue. Optionally, tissue properties are updatedonly when a catheter's position is detected near the modeled tissue,e.g., the distance of a distal end of the catheter distance from thetissue surface is smaller than a predetermined threshold.

In some embodiments, once a probe is inserted 210, dynamic imagemodification (referred to in FIG. 2 as arrow A) is provided, optionallyautomatically. In some embodiments, automatic image modification isprovided based on detection of the catheter's position and/ororientation relative to the modeled tissue. Optionally, once thecatheter is identified to cross over a predetermined distance towardsand/or away from the tissue, the presented image is modified. In someembodiments, image modification comprises modifying the viewpointlocation used to generate the model, for example, modifying the locationfrom within an organ comprising the modeled tissue to a location outsidethe organ. In some embodiments, modifying includes switching betweenimages. Alternatively, modifying includes adding or removing an image.

In some embodiments, a viewpoint location is automatically modified whendetecting a catheter getting close to a selected tissue target. Theselection of the tissue target may be, for example by planning, byoperation of a user interface that deviates from a plane, or otherwise.In some embodiments, getting close is determined when sensing a positionof the catheter relative to the defined target, optionally combined withan evaluation of the catheter's orientation with respect to the definedtarget. In some embodiments, a threshold distance for modifying theviewpoint location is also affected by the orientation of the catheterwhen approaching the target. For example, if the orientation of thecatheter is facing away from the direction of the target site, thethreshold distance to shift points-of-views would be a smaller distancebetween the catheter and the target site than if the orientation of thecatheter is facing towards the target site. In some embodiments, aninset and/or a preview of the modified image flicker temporarily. Insome embodiments, only after the surgeon persists in the detecteddirection, the modified image remains stable. In some embodiments, oncean image is stable, it would not be modified again for a predeterminedperiod of time, such as in the range of 1-2 sec, 2-5 sec, or 5-10 sec.

In some embodiments, an image is provided as viewing a cross-section ofa tissue depth. Optionally, dynamic image modification includesautomatic dynamic zooming in into regions of interest. In someembodiments, a plurality of images is shown simultaneously on the sameuser interface. Optionally, a single image can automatically replace theplurality of images, such as for example, when detecting an onset of aprobe's operation, a single image depicting its operation is provided.

Optionally, vice versa automatic image modification from a single imageto multiple images is provided.

Identify Target

In some embodiments, the catheter is detected as approaching a selected(e.g., plan-selected) target 214, optionally by dielectric measurements.In some embodiments, a catheter is detected as approaching a target bydetermining the position of a distal end portion of the catheter probe(e.g., determining the position of one or more electrodes and/or sensorslocated on catheter, e.g., the distal end thereof). Alternatively oradditionally, approaching a target may be detected by calculating aposition of the distal end portion of the catheter probe based on one ormore electrical and/or dielectric and/or thermal parameters (e.g.,field, current, voltage, and/or impedance). Alternatively oradditionally, approaching a target may be detected by correlation ofmeasured parameters with values of the same parameters obtained by asimulation. The simulation may include simulated positions of asimulated catheter probe within a 3-D model, the model associated withestimated dielectric parameter values and/or with estimated thermalparameter values.

Optionally, the simulation is iteratively updated according to one ormore parameters measured in real-time, for example, electricalparameters and/or thermal parameters of tissues, measured by intra-bodysensors. The electrical parameters may include dielectric parameters,such as impedance of the myocardium of the heart (or othertarget-related tissue), and/or conductivity of the blood, and/or thermalparameters such as thermal conductivity and/or heat capacity. Themeasured values may be fed back into the simulation, to update theestimated electrical values and/or thermal values with the measuredparameters values. The simulation may be re-generated to generate anupdated set of simulated positions for correcting the measured physicallocation of the distal end of the catheter. Optionally, the measuringand updating of the simulation are iterated, to improve the accuracy ofthe corrected distal end position. The iteration may be performed toreach a target accuracy, such as an accuracy fine enough for performingthe treatment procedure.

In some embodiments, once a target is approached, dynamic imagemodification B is provided. Exemplary dynamic image modification can beseen in FIGS. 6A-F and 9A-G. Optionally, when the catheter is detectedto be near a target site, a close up view is provided. In someembodiments, a planned target is visually presented as a graphicalobject, such as a path, matched to the 3-D surface of the 3-D model ofthe tissue presented, such as seen for example in FIGS. 6A-F and 9A-G.Optionally, a planned target only appears after zooming in over themodeled tissue. In some embodiments, the resolution of the graphicalobject is higher when viewing the tissue more closely, such asillustrated in FIGS. 6C and 6D.

In some embodiments, if no target is identified after a pre-set timeperiod, it is possible a catheter is lost 213 with respect to its targetsite. Optionally, at this point, the view is modified automatically toshow an outer view of the target area and/or organ.

Ablation

In some embodiments, when contact is detected between the probe and thetissue surface, and/or when ablation onset is provided 216, the view isshifted C, for example to a cross-sectional view of the treated tissue.In some embodiments, only the planned tissue region is visuallyrendered. Alternatively, a simulated section is provided with at leastone neighboring planned region, as illustrated in FIGS. 7A-F.

Alternatively, a simulated region is shown surrounded by its immediatesurrounding tissue, as illustrated in FIGS. 9A-G and FIG. 11.Optionally, once a planned ablation procedure is complete, the image ismodified automatically to present an overview of the procedure, such asillustrated for example in FIG. 8 and FIGS. 10A-B.

In some embodiments, an operational procedure plan is automatically ormanually changed in real-time during a procedure 217. Optionally,updating of the plan is according to deviations due to differencesbetween planned and intended actions during the operational procedure;for example, movement of a lesion site to a new position, by accident oron purpose. Optionally, updating is according to new data describingfeatures of the operational procedure site overall, for example,previously unknown details of anatomy (such as may occur, for example,as a consequence of normal inter-subject anatomical variability, normalintra-subject changes in anatomy, and/or disease). Optionally, updatingof the plan is according to tests carried out which indicate that anintended effect of the treatment (e.g., blockage of electrical impulseactivity) is incomplete or otherwise not as anticipated by the existingplan. Automatic updating may comprise accepting data indicating, forexample, any of the just mentioned conditions, identifying that a plandeviation has occurred, and formulating a new plan which compensates forthe deviation.

Validation

In some embodiments, after completing an ablation process and/or afterdisplaying an ablation overview, validation 218 takes place, optionallyto validate an effective block of pulse propagation. In someembodiments, dynamic image modification D is provided when detectingonset of validation, optionally automatically modifying to an imageshowing an overview of the ablation process, optionally graphicallypresenting actual ablation simulation and/or planned ablation paths.Validation views and visual representations are exemplified in FIG. 12.

In some embodiments, if validation fails 222, i.e. no sufficientblocking of pulse propagation is accomplished, a repeated ablation isoptionally provided. In some embodiments, when validation is detected asfailed, a detected proximity of a catheter to the failed ablation siteresults in automatic view shifting B to an ablation view.

In some embodiments, after validating, even if validation is successful,more ablation targets are pursued 224, and optionally the presentedimage is automatically modified, for example to navigation view A. Ifnot more validation is needed, the procedure is optionally finished 220.

Exemplary Model Renderings

Reference is now made to FIGS. 1A-1E, showing flow charts of processesfor rendering a 3-D model, optionally in real-time, in accordance withsome embodiments of the invention.

Some of the processes of FIGS. 1A-E, in some embodiments, include theuse of a 3-D model of a tissue, optionally a tissue surface. In someembodiments, the 3-D model comprises mesh data; for example as iscommonly used in defining structures for computerized visual renderingof 3-D structures. In some embodiments, the 3-D model specifiespositions (and usually also connections among positions, and/orpositions joined by the extent of a common surface and/or materialvolume), corresponding to positions of surfaces of a target body tissueregion to be visually rendered for presentation. Optionally, thegeometry of positions defining an interior shape of the surface is alsorepresented (for example, where presentation includes the use oftransparency and/or cross-sectional views). Surfaces represented areoptionally external (e.g., organ surfaces; not necessarily surfacesvisible externally to the body) and/or internal (e.g., lumenal) surfacesof the target body tissue region. In some embodiments, a 3-D model isderived from anatomical data; for example, appropriately segmented 3-Dimage data of a patient.

In some embodiments, at least a portion of the surface presented by the3-D model rendered with at least one material appearance property (MAP).As the term is used herein, MAPs comprise any properties associated topositions in a virtual environment for visual rendering according tosimulated optical laws, and which affect how a surface and/or itsenclosed volume are visualized within a 3-D rendered space. MAPs areusually, but not only, assigned to surface positions of the 3-D model.MAPs are optionally assigned to volumes defined by surfaces of the 3-Dmodel. MAPs can also be assigned to the virtual environment (e.g., aslighting parameters) in such a way that they affect material appearance.

Creating the visual rendering in some embodiments treats surfaces and/orvolumes as comprising virtual material. A virtual material, in someembodiments, is subject to simulated optical rules approximatingprocesses such as reflection, scattering, transparency, shading, andlighting. Not every optical rule used in visual rendering is a copy of areal-world rule; the art of computer rendering includes numeroustechniques (for achieving both realistic and deliberately unrealisticresults) which apply simulated optical rules that have no directphysical equivalent. For example, bump mapping simulates surface heightirregularities by manipulation of reflectance. Ambient occlusion is anefficiently calculable lighting effect defined in association withsurface maps, wherein light sources are treated as approximations.

Additionally, it should be understood that not everything discussedherein as a material appearance property is necessarily a property of avirtual material as such. For example, in some embodiments, certaineffects of lighting are implemented using sources which are virtuallyplaced remote from a surface they illuminate (and so, not defined asproperties of the surface's virtual material). Nevertheless, insofar asthe properties of these lights affect the appearance of the material,they are classed within the meaning of MAP. Also herein, where needed tomake a distinction, the phrase “material properties of appearance” isused to indicate MAPs defined for a virtual material as such (ratherthan as part of the lighting environment).

Optionally, baseline MAPs data are initially assigned to surfaces(optionally, volumes) defined by the 3-D model so that these surfacesresemble, when suitably rendered for visual presentation by userinterface, simulated versions of the tissue they represent. For example,a muscular organ such as the heart is optionally rendered as a mottledreddish-pink, optionally with additional surface properties such asscattering, roughness, specular reflection properties, and/or overallreflectivity defined to give it irregular gloss evocative of a wetsurface. Highly vascular structures such as liver and kidney tissue areoptionally represented with a more uniform and ruddier hue.

Optionally, baseline MAPs data takes into account tissue state datawhich characterizes tissue beyond its geometrical shape. In someembodiments, for example, 3-D nuclear imaging data is optionally used todistinguish between healthy and scarred cardiac muscle tissue. Scarredtissue is optionally distinguished in presentation by differences in oneor more virtual optical properties from healthy tissue (e.g., rougher,duller, and/or grayer in appearance).

In some embodiments, procedure effects, whether measured, estimatedand/or calculated, are rendered onto the baseline MAPS, and/or renderedas providing other visual texture characteristics; for example,alterations to MAPs governing visual roughness and/or specularreflection are made (e.g., ablated tissue becomes “dull” and/oredematous tissue becomes “smooth”).

In some embodiments, changes in MAP from baseline are optionally chosento reflect conventions or expectations of how a procedure affectstissue. Alternatively or additionally, changes in MAP from baseline areoptionally exaggerated for clarity. For example, even if an alreadywell-perfused tissue does not actually become “redder” when inflamed, itis still an option, in some embodiments, to apply MAP reddeningcomprising, e.g., color shift, brightening, and/or increase insaturation to indicate an inflamed state. Similarly, heating and coolingare optionally indicated by assigning “redder” or “bluer” MAPs; addingan icy gloss to cooled-off tissue; adding smoke, glow, and/or flame toheated tissue; etc. In another example, the surface of a region injectedwith a substance such as Botox® (Allergan, Inc., Irvine Calif.) isoptionally represented as having MAPs which give it a “smoother”appearance (e.g., bump map texturing is suppressed), whether or notsmoothness relates to a realistic appearance change.

In some embodiments, MAPs are defined using light source positioning,for example, to selectively illuminate (e.g., in simulation of a laseror flashlight light beam) a tissue region. As for the examples oflighting, this optionally comprises a MAP having an underlyingdefinition in data and/or software which is positioned outside thevirtual material of a surface whose display appearance is affected.

Reference is now made to FIG. 1A, showing a flowchart exemplifying aprocess for rendering a simulated indicating marker over a 3-D tissuemodel, in accordance with some embodiments of the invention. Theindicating marker may be used, for example, as a point of referenceand/or as an indicator to results of one or more measurements. Forexample, an indicating marker may be used as a point of reference of theposition and/or facing direction of the catheter probe relative to thepresented tissue. Alternatively or additionally, the indicating markermay be used to point in the direction of a selected (e.g., planned)target site, which may comprise tissue targeted for approach,measurement, and/or treatment. Alternatively or additionally, theindicating marker may be used for marking one or more regions. Theregions to be marked may be, in some embodiments, planned, calculated,selected by user input, and/or estimated.

Optionally, the process includes assigning a graphical object to theindicating marker, optionally having a visual presentation related toits meaning. For example, an indicating marker representing a point ofreference may be assigned a target sign and/or an arrow pointing in thedirection of the point of reference. In another example, an indicatingmarker representing a region may be assigned a delimiting line acrossand/or surrounding the region to be marked.

In some embodiments, the assignment of graphical objects to theindicating markers is pre-set, for example, before the catheterizationprocedure begins. In some embodiments, at least some visual appearanceproperties of the graphical objects assigned to an indicating marker isset in real-time, for example, a color of a graphical object may be setbased on the color of the tissue it covers, the shape of the graphicalobject may be set based on the target pointed by the indicating marker,etc.

In some embodiments, a region to be marked with the indicating markerover the 3-D model is determined 104. Optionally, the region to bemarked is determined by determining a location in the 3-D model togetherwith a size and/or a shape of the region. In some embodiments, theposition of the region to be marked is determined by measurementsprovided in a specific position in relation to the real tissue.Alternatively or additionally, the position of the region to be markedis determined based on a decision made in advance, such as in the caseof preplanning. Alternatively or additionally, the position of theregion to be marked is determined based on spatial relationship betweenan object and the tissue, such as for example, the location of thecatheter probe in relation to the tissue.

Optionally, the size of the region to be marked corresponds to databeing represented by the indicating marker. For example, whenreferencing the location of a catheter probe relative to the modeledtissue, a larger or smaller region may signify a closer or fartherlocation of the probe.

In some embodiments, the shape of the region to be marked corresponds todata collected in real-time. The data may include, for example,measurements, and/or calculations based on real-time measurements,and/or estimations based on real-time measurements and/or calculations.For example, the shape of the region to be marked may correspond to ameasured spread of heat and/or electrical current through the tissue.

In some embodiments, the indicating marker is deformed to congruentlymatch the 3-D model at the determined region to be marked as in step106. As used herein, congruently matching comprises deforming agraphical element to fit with a shape defined by a 3-D model in aplurality of positions, to generate an image of the 3-D model covered bythe graphical element, not necessarily on the surface of the model. Insome embodiments, fitting over a plurality of positions comprisesdeforming the graphical element to spread over a plurality of planesdefined by the geometric surface of the 3-D model.

In some embodiments, the process includes a step 108 of rendering the3-D model to include the deformed indicating marker at the determinedregion to be marked. In some embodiments, the indicating markerindicates a direction of a selected target site. Alternatively, theindicating marker indicates a planned path. Alternatively, theindicating marker indicates a field of view viewed from a location alongthe catheter probe, the location being determined by a measured positionand facing direction of a distal end of the catheter probe.

In some embodiments, an appearance of the indicating marker indicates arelative location of the catheter probe with respect to the tissuesurface, the relative location being determined by a measured positionand facing direction of a distal end of the catheter probe relative tothe tissue surface. Optionally, a size of the region indicates adistance between the catheter probe and the tissue surface.Alternatively or additionally, a visibility of the indicating markerindicates a distance between the catheter probe and the tissue surface.Alternatively or additionally, an aspect ratio of the region indicatesan orientation between the catheter probe and the tissue surface.

In some embodiments, it is identified that an indicating marker shouldbe presented, optionally based on rules pre-associated with input whichis expected to be acquired during the catheterization procedure. In someembodiments, input includes the identified onset of a navigationprocess, such as for example, when identifying navigation tools beingpowered on. Alternatively or additionally, input includes identifyingthe onset of ablation, for example, by detecting operation of thecatheter probe, and/or contact with the tissue, and/or heat.

Reference is now made to FIG. 1B, showing a flowchart exemplifying aprocess for rendering a geometric tissue model based on estimated data,in accordance with some embodiments of the invention.

At 120, input is collected during a catheterization procedure.Optionally, input is measured in real-time, and/or calculated from suchmeasurements. At 122, an effect is estimated based on the input. Forexample, when the collected input is a start of an operation of anablation probe, an effect of the operation of the ablation probe may beestimated. For example, it may be estimated that heating takes place.Optionally, a plurality of inputs is combined to characterize theestimated effect. For example, the properties of the tissue are taken inconsideration when estimating the effect of starting operation of anablation probe.

At 124, parameters characterizing a region of the 3-D model to be markedare determined based on the estimated effects, optionally taking intoaccount the measured input. The parameters may include, for example,shape, size, and/or position of the region to be marked. For example, aregion to be marked may be determined to have a symmetric shape if thetissue is uniform and the effect of the probe is estimated to beuniform. Alternatively, a region to be marked may have an irregularshape when an effect is estimated to affect in a non-uniform mannerand/or when non-uniform tissue characteristics are detected, such as ascar, and/or edema and the like.

In some embodiments, calculating a shape comprises calculating an areaof an ablation point. Alternatively or additionally, calculating a shapeincludes calculating a depth of an ablation point. Alternatively oradditionally, it includes calculating a path of a plurality of ablationpoints.

Optionally, an estimated effect is presented as a function of time. Forexample, when starting an ablation, it is estimated that heat will bedissipated, after which the tissue would be cooled again. In someembodiments, at the onset of an ablation, a sequence of events as afunction of time is presented. In some embodiments, the shape of thetissue surface is recalculated at different times during the procedure,and the presentation thereof is modified accordingly. Optionally, theshape and the material appearance properties indicate an increasingspread of a lesioning effect.

At 126, at least one material appearance property (MAP) is selected forthe region to be marked. Optionally, the MAP is selected from a databasecomprising a plurality of MAPs. Optionally, each MAP in the database isassociated with at least one estimated effect. Optionally, the databaseincludes associations between MAPs and effects.

At 128, the 3-D model is rendered with the determined region beingmarked using the selected at least one MAP. In some embodiments, theestimated effect is dynamic, for example, in the sense that it evolvesover time, and accordingly the rendering is dynamic. In someembodiments, the modeled shape of the region to be marked changes overtime, and/or the size of the region changes over time, and/or theposition of the region changes over time, and/or the selection of MAPschange over time.

Reference is now made to FIG. 1C, showing a flowchart exemplifying aprocess for providing a point of reference for rendering a 3-D tissuemodel by simulation of illumination, in accordance with some embodimentsof the invention.

In some embodiments, a catheter probe, and optionally specifically thedistal end of the catheter probe, is detected to determine 132 itsposition and/or facing direction relative to a tissue. Optionally, thetissue region comprises a body lumen.

In some embodiments, a 3-D model of the tissue is rendered to simulateillumination 136 as if originating from the determined position of thecatheter probe and illuminating in the direction of the determinedfacing direction of the catheter probe. In some embodiments, the 3-Dmodel is rendered from a viewpoint located along the catheter probe,causing the illumination to simulate a flashlight. Optionally, thetissue modeled is visible beyond the simulated beam of the flashlightdue to simulation of at least one second illumination source, such asfor example, simulation of ambient light. In some embodiments, the 3-Dmodel is rendered as viewed from a viewpoint offset to said distal endof said catheter probe.

Optionally, the illumination simulated to be originated from thecatheter probe is viewable at 136 from a side of the model opposite tothe illumination site, i.e. opposite to the location of the catheterprobe, optionally from a viewpoint located outside of the organcomprising the catheter, such as shown, for example, in FIG. 3B and 3-D.In some embodiments, illumination is viewable from the other side byrendering the tissue at least partially transparent. In someembodiments, two images are provided, one rendered from a viewpointinside of the organ and the other rendered from a viewpoint outside theorgan, both having a respective illumination. A potential advantage ofshowing the same illumination from two different viewpoints is toprovide both a reference of the position and a reference of a facingdirection of the probe in a single glance.

In addition, it provides an easy and intuitive interpretation of theorientation of the probe within the organ, in the context of itsproximal environment when viewing from within, and in the context of theentire organ when viewing from outside and thus provides 138 a point ofreference to the surgeon. In some embodiments, the determining and therendering is provided iteratively during at least a portion of thecatheterization procedure.

Optionally, the method comprises presenting the 3-D model as viewed fromat least two viewpoints simultaneously, a first viewpoint being insidean organ comprising the tissue region and a second viewpoint beingoutside the organ, and wherein both presentations include the simulatedillumination as if originating from the determined position and in adirection of the determined facing direction of the catheter probe.

In some embodiments, the illumination is simulated to be uneven across asimulated illumination beam. Alternatively or additionally, a center ofthe illumination is calculated according to a position and facingdirection of the catheter probe relative to the tissue region.Optionally, the center of illumination is graphically presented byincreased illumination intensity at a center of said beam. In someembodiments, a second illumination sourced from a position distinct fromthe position of the distal end of the catheter probe is provided.Optionally, the second illumination is simulated to face a directiondistinct from the facing direction of the distal end of the catheterprobe. Alternatively or additionally, the second illumination issimulated as an ambient light source.

In some embodiments, a material appearance of a surface of the tissueregion is selected and the material appearance is optionally simulatedto be affected by the illumination. Optionally, the tissue model isrendered to appear at least partially translucent to the simulatedillumination.

Reference is now made to FIG. 1D, showing a flowchart exemplifying aprocess for automatically modifying the image presenting a 3-D tissuemodel, in accordance with some embodiments of the invention.

In some embodiments, during a procedure, a surgeon uses at least onescreen, having a user interface provided to guide the surgeon throughoutthe procedure, for example, by presenting tissue models, indicatingmarkers, numerical data and so forth. In some embodiments, the imagepresenting the modeled tissue is modified automatically during thecatheterization procedure, optionally in response to input collectedduring the procedure. In some embodiments, an image which is estimatedto be the most helpful to the surgeon at an identified condition of theprocedure is generated.

In some embodiments, at 140, each of a plurality of conditions isassociated with an image for presenting the 3-D model. In someembodiments, an image is defined by a plurality of parameters.Optionally, the parameters may include a region to be marked (includingposition, shape, and size of the region), and/or MAPs selected for theregion. Alternatively or additionally, the parameters comprise aviewpoint from which the model is to be presented to the surgeon, azooming in or zooming out, a single image or a plurality of images, andso forth.

In some embodiments, at 142, a condition is identified and at 144, theimage associated with the identified condition is automaticallygenerated. In some embodiments, the plurality of conditions relate to acatheter probe's position and/or operation with respect to the modeledtissue. For example, a condition may comprise a distance between adistal end of a catheter probe and a tissue surface shorter than apre-set threshold. Alternatively or additionally, a condition maycomprise the tissue surface including a selected (e.g., planned for anaction of the procedure, or otherwise indicated) site. Alternatively oradditionally, a condition may comprise changing an operation state of acatheter probe, such as turning the power on or off. Alternatively oradditionally, a condition may comprise detecting a contact of a distalend of a catheter probe with a surface of the modeled tissue.

In some embodiments, once a condition is identified, its associatedimage is automatically generated. Optionally, an image is generated bymodifying the viewpoint used to render the model. Alternatively oradditionally, an image is generated by zooming in or zooming out of thefield of view of the model. Alternatively or additionally, an image isgenerated by changing the viewing angle of the image, such as forexample, presenting a top surface of the modeled tissue surface area orpresenting a cross-section of the depth of the modeled tissue.Alternatively or additionally, an image is generated by adding orremoving an image, for example when switching between a single image toa plurality of images, and vice versa. Alternatively or additionally, animage is generated by rendering the model to include a graphical objectacross a region of the model.

Reference is now made to FIG. 1E, showing a flowchart exemplifyingrendering of a 3-D model of an inside environment of an organ, as ifviewed from a location distinct from any position along the catheterprobe, in accordance with some embodiments of the invention.

In some embodiments, a position and/or facing direction of a catheterprobe are determined 152. Optionally, the position and/or facingdirection determined are of the catheter probe's distal end. Optionally,the catheter probe position and/or facing direction are continuouslymeasured during a catheterization procedure. In some embodiments, a 3-Dtissue model is rendered at 154 to be viewed from a viewpoint locationdistinct from any position along the catheter probe, optionally suchthat the tissue targeted by the catheter probe and the distal end of thecatheter probe could be modeled in a single field of view. Optionally,the field of view further includes a region to be marked across themodeled tissue. In some embodiments, the location is found further awayfrom the catheter distal end than the modeled tissue surface.Optionally, the rendering is dynamic and is updated with the on-linemeasurement of the catheter probe position and/or facing direction.

In some embodiments, a graphical presentation of the catheter distal endis overlaid over the rendered model in step 156. Optionally, theoverlaid distal end is dynamically presented by modifying the graphicsto represent the detected facing direction of the catheter distal end.It is a potential advantage to present the tissue as viewed from a pointfurther away from the distal end of the catheter probe, and potentiallyadvantageous to overlay its graphics, by providing to the surgeon arendered model having an easily detected rendering viewpoint.

Exemplary Navigation

Reference is now made to FIG. 3A to 3-D, exemplifying tissue modelrendering as viewed from various viewpoint locations with respect to thecatheter, in accordance with some embodiments of the invention.

In some embodiments, a plurality of viewing perspectives is presentedsimultaneously, for example, viewing inside the patient-specific organ,such as shown in FIGS. 3A and 3C, together with viewing at least aportion of the patient's organ from outside, such as shown in FIG. 3Band 3-D.

In some embodiments, a 3-D model is presented using a viewpoint beingoffset to the catheter probe and/or further away from the renderedtissue surface than the distal end of the catheter probe, defining a“first person” view, as shown in FIGS. 3A and 3C. In some embodiments,presenting the 3-D model also includes graphically presenting overlayingat least a portion of the distal end of the catheter probe. A potentialadvantage of overlaying the catheter distal tip over the 3-D model is inreducing the cognitive load which may be on a surgeon, as opposed towhen he is provided with model viewpoints being along the catheterwithout actually seeing the catheter and having to interpret thecatheter's position and/or orientation from deriving the viewpoint usedto render the tissue.

In some embodiments, a plurality of viewpoints is provided, optionallypresenting the same probe position and/or orientation. In someembodiments, using automatic dynamic image modification, tissueappearance and tissue shape changes can be viewed from the inside of theorgan and/or can be viewed from outside the organ, optionally dependingon the catheter's position and/or orientation and/or operation state. Atleast in some cases, having the same graphical marking shown in aninside view and seen from an outside view, helps a surgeon to orienthimself.

In some embodiments, a catheter 300 is simulated to illuminate thetissue surface at 302 like a flashlight, e.g. simulated to produce alight beam as if originating from the catheter distal end. Optionally,the catheter is simulated to illuminate in the direction it is facing.In some embodiments, the catheter is simulated to project a flashlightproducing a wide floodlight, having the potential advantage ofsimulating light over a relatively wide surface area, which likely dueto its areal coverage, is also optionally detectable from a viewpointlocation being outside the organ 310, as shown in FIG. 3B and 3-D.Alternatively, the catheter is simulated to project a narrow beam, whichpotentially serves as an indicating marker, optionally indicative of thecatheter's facing direction.

In some embodiments, light simulated to be projected from the directionof the catheter is shown by simulating diffuse lighting and/or specularlighting, in accordance with a 3-D shape defined by the tissue model.

In some embodiments, additionally to the flashlight illumination oralternatively to it, an indicating marker 304 illustrating the positionand orientation of the catheter is graphically presented. Optionally,indicating marker 304 congruently matches the surface shape of themodeled tissue.

Reference is now made to FIGS. 4A-B, showing a simulation of theflashlight feature, in accordance with some embodiments of theinvention. An aspect of several embodiments of the invention relates tosimulating illumination projecting from a probe from the direction theprobe is facing. In some embodiments, the illumination is simulated tobe projected onto the surface of a 3-D model. Optionally, illuminationis provided as a diverging, wide floodlight beam. Alternatively oradditionally, illumination is provided as a coherent, narrow light beam.In some embodiments, illumination is projected from the inside of atissue model and seen from the outside of the tissue model.

FIGS. 4A and 4B illustrate that an image generated according to someembodiments of the present invention may include different portions ofthe tissue surface lighted to differing degrees, for example, independency on the distance between the lighted surface and the distalend of the catheter. In the figures, tissue surface region 424 is closerto the distal end of catheter 300 than surface region 422; and isilluminated with stronger light.

FIG. 4A illustrates a viewpoint used to render the model of a “thirdperson” view, optionally overlaying a representation of the catheter'sdistal end. As used herein, a “third person” view includes presentingthe 3-D model having a field of view which includes the distal end ofthe catheter probe, the tissue region being viewed by the distal end ofthe catheter probe 300, and optionally the indicating marker 304signifying the viewpoint of the distal end of the catheter probe. Forexample, FIG. 4A exemplifies a viewpoint being above the catheter probeand being further away from the tissue than the distal end of thecatheter probe. In this exemplary embodiment, an overlay of the distalend of the catheter probe is provided.

FIG. 4B exemplifies a zoom out of an out-of-organ view, of the sameconfiguration shown in FIG. 4A, but shown from outside the organ. Insome embodiments, closer tissue surface portions such as 424 arerendered using MAPs providing the appearance as if the tissue surfacereflects light more intensely and in a more focused manner than tissuesurface portion 422.

In some embodiments, the viewpoint used to render the tissue model isshifted automatically, for example, from the view of FIG. 4A to that ofFIG. 4B or vice versa. Optionally, a modification in presented images isbased on probe position and/or probe orientation and/or probe trajectoryand/or probe activity. For example, once an ablation process isdetected, the image may be modified to a graphical animationillustrating the ablation procedure, optionally graphically visualizedbased on real-time physiologic input.

Reference is now made to FIGS. 5A to 5D, illustrating ageometric-specific indicating marker 304, in accordance with someembodiments of the invention. In some embodiments, an indicating markeris rendered across a region of the surface of a 3-D tissue model.Optionally, the projection is from a viewpoint defined along thecatheter probe and/or facing the facing direction of the catheter probe.Alternatively or additionally, the viewpoint is in the direction of aselected (e.g., selected by a plan and/or by an indication made byoperation of a user interface) target site. FIGS. 5A-D illustrate fourcongruent matchings of indicating marker 304 over the 3-D modeled tissuesurface provided in a region to be marked, which is optionallydetermined by the relative position and/or facing direction of thecatheter probe relative to the modeled tissue.

A potential advantage of rendering a congruently matched indicatingmarker and/or flashlight illumination, both deformed to the geometric3-D surface of the tissue model, is the dynamic nature of the markerwhen moving over the surface of the modeled tissue, retaining thereactiveness of the graphical object to its virtual environment. This isdistinguished from a simple icon overlay which does not match to thespecific tissue surface region it is rendered on.

Reference is now made to FIGS. 5E to 5G, illustrating a schematic,surface shape-specific indicating marker 504 fitted onto a surface of aschematic 3-D model 500, in accordance with some embodiments of theinvention. An indicating marker is shown as a schematic example as thegraphical object of triangle 504. Marker 504 may include the sides ofthe triangle and/or the interior of the triangle. FIGS. 5E-5G illustratehow marker 504 is deformed to match the 3-D model 500, at a plurality ofpositions, illustrated for example in these schematic illustrations asthe meeting points of marker 504 with lines making up grid 501. Alsoexemplified herein, is that marker 504 is rendered across a region ofthe 3-D model, the region is shown by the delimitation of marker 504 inthe form of a grey line.

FIG. 5E illustrates marker 504 in the form of a triangle being deformedto match 3-D model 500 in the form of a sphere. In this example, marker504 is deformed to have a concave shape, fitted to the 3-D geometricsurface of model 500.

FIG. 5F illustrates marker 504 in the form of a triangle being deformedto match 3-D model 500 in the form of a convex surface. In this example,marker 504 is deformed to have a convex shape, fitted to the 3-D convexgeometric surface of model 500.

FIG. 5G illustrates marker 504 in the form of a triangle being deformedto match 3-D model 500 in the form of a plane. In this example, marker504 is deformed to have a perspective shape, fitted to the 3-D plane ofmodel 500.

Exemplary Target Identification

Reference is now made to FIGS. 6A to 6F, showing a simulation ofidentifying a target and starting an ablation, in accordance with someembodiments of the invention. FIG. 6A illustrates a visualrepresentation of catheter probe 300 being oriented toward the leftpulmonary veins, illustrated by left superior pulmonary vein 602 andleft inferior pulmonary vein 604. Also shown are right superiorpulmonary vein 606 and right inferior pulmonary vein 608.

In some embodiments, when a target is identified, either through plannedsettings and/or identification of user input indicative as identifying atarget, the visual representation of the 3-D model is modified,optionally automatically. In some embodiments, modification of the 3-Dmodel is provided by modifying the viewpoint used to render the model,such as for example, zooming in on the target site (as shown in FIG.6B), or for example, switching into a cross-section view (as shown inFIG. 6F). Alternatively or additionally, modification of thepresentation of the 3-D model is provided by presenting an indicatingmarker, such as for example, a planned path and/or marking (as shown inFIGS. 6C-6E).

Exemplary Ablation Visualization

In some embodiments, ablation treatment of a tissue region (for example,cardiac tissue of the atria) comprises the formation of a substantiallycontinuous lesion of tissue which serves as a block to conduction. Insome embodiments, the targeted region to block is along a lesion path610 formed from a plurality of sub-lesions 620 arranged along it in asubstantially contiguous fashion. Shown in FIGS. 6A-F and 7A-F, forexample, is a lesion path 610 which encircles two pulmonary veins 602and 604 of a left atrium (a view from inside the atrium is shown).

In appearance, FIGS. 6A-6F comprise visually rendered images (by a 3-Dgraphics engine) of an RF ablation probe 300 and its position relativeto tissue targeted for ablation. Optionally, the rendering is in color,and/or otherwise using applied material appearance properties conveyingthe vital appearance (e.g., properties of roughness, specularreflection, etc.) of the tissue (black and white is shown herein forpurposes of illustration).

In some embodiments, once catheter 300 is detected to be orientedtowards a target site, the viewpoint used to render the model ismodified, optionally, by zooming in, as exemplified in FIG. 6Billustrating a close up on the left pulmonary veins. Alternatively, thisview is triggered when contact is sensed by a sensor on the probe, suchas a pressure sensor and/or dielectric sensing of contact. Thetriggering is optionally visually implemented as a jump from a widerangle view with the probe out of contact to a close-up of the probecontacting tissue. Optionally, transition from no-contact to contact (orvice versa) is visually shown by a short bridging animation. In someembodiments, continuous sensing of probe position and/or probe distanceto the tissue wall, allows any jump in a sensed transition betweencontact and non-contact to be smoothed out using actual position data.

In some embodiments, zooming in or zooming out is dynamic. Optionally,zooming in leads to increased resolution of guide markers. Exemplaryguide markers 610 and 620 are illustrated in FIGS. 6C-6E, where eachfigure illustrates a closer view of the target site, and each closerview shows more details, for example, the ablation path 610 is firstshown in FIG. 6C and the ablation area markers 620 are then shown inFIG. 6D. The ablation area markers may correspond to planned ablationsub-lesions. In some embodiments, a single ablation area marker 622 isdetected to be the target, and is optionally maintained at the center ofthe modeled region.

Optionally, adjacent ablation markers to the left 624 and/or the right626 are also presented, potentially maintaining the larger view context.

In some embodiments, once catheter 300 is detected to contact ablationmarker 622, the view is automatically switched, optionally to illustratea cross-sectional view of the depth of the tissue marked by marker area622. In some embodiments, markers 624 and/or 626 are also shown in thisview, optionally having a dull and/or transparent appearance, to furtherfocus the surgeon on the active marker being in contact with the probe.Optionally, the marker in contact is differentiated from other markersby simulating material appearance relating to at least one tissueproperty, such as for example simulating tissue layers, as shown inmarker 622 in FIG. 6F. A potential advantage of showing details oftissue properties only in a marker area which is in contact with thecatheter is reducing the cognitive load of a surgeon by focusing hisattention, and also potentially reducing the load of a controller havingto render these tissue properties to only a delimited area and/or depth.

Reference is now made to FIGS. 7A-7F, which schematically illustratevisual rendering of various stages of lesioning to block tissueconduction, for example for the treatment of atrial fibrillation,according to some exemplary embodiments of the present disclosure. Itshould be noted that FIGS. 7A-7F show the tissue in cross-section, whichis a potential benefit for conveying to a surgeon information aboutachieved lesion parameters such as lesion depth and/or lesiontransmurality.

In FIG. 7A, catheter probe 300 is shown approaching ablation site 622.

Optionally, adjacent ablation sites 624 and 626 are shown in a“non-active” representation, such as for example, looking dull, and/orrepresented in non-informative block coloring, and/or being transparent.Such a presentation may assist a surgeon in focusing on the targetedsite only. In some embodiments, the different representations mayindicate ablated and non-ablated sites.

For example, ablation site 622 may be the last site to be ablated alonga path starting at 624, going through 626 and ending at 622. In someembodiments, FIG. 7A may be presented simultaneously with presentingFIG. 6D. Catheter probe 300 may comprise at least one electrode, actingas an ablation electrode, is moved sequentially along path 610 (FIG.6D), ablating at a plurality of locations to create a chain sub-lesions620 at each location. Lesioning is performed according to clinicallyrelevant parameters for generating transmural atrial wall lesions.

Illustrated in FIG. 7B is an optional representation of catheter 300being in contact with ablation site 622 through surface 702. Surface 702is shown as being pushed by catheter 300 into the depth of the tissue,resulting in ablation site 622 being at a distinct level than itsadjacent sub-lesions 624 and 626 (see also FIG. 6F).

In some embodiments, once ablation onset takes place, simulated materialappearance changes are provided. For example, FIG. 7C illustratessurface 702 by graphically presenting warm, bright coloring, optionallyoriginating at the simulated catheter 300 tip engaging with the tissuesurface. This presentation may be the result of data indicative ofactual warming of ablation site 622. The data may be collected inreal-time, interpreted to estimate a temperature rise. Based on theestimated temperature rise, material appearance properties shown in FIG.7C may be selected, as discussed, for example, in the context of FIG.1B. As heating continues, real-time data may be collected, and thetemperature may be estimated to rise further, causing a new selection ofthe MAPs, for example, as shown in FIG. 7D. In some embodiments, whentransmural ablation is achieved, heat is shown to propagate into theentire depth of tissue 706, as shown in FIG. 7E.

In some embodiments, once ablation is detected to be done and/orcalculated to be done, tissue 706 may be estimated to be scarred and/orcooler, and rendered using dull, cold colors. When catheter probe 300 ispulled away (FIG. 7F) Surface 702 is released from the pressure exertedby the catheter probe, optionally leading to the return of the surfaceto its original height.

In some embodiments, visual rendering of the geometric surface of the3-D anatomical model of the patient's tissue or organ includes modifyingthe appearance based on intermediate results which can be monitoredwhile the procedure is carried out. For example, properties of a lesionmay be estimated during an ablation in progress (for example, based onmeasurement results of dielectric property and/or temperature) andvisualized by having the appearance of the geometric surface changeaccording to the measurements, such as by increasing the warmth and/orintensity of a color of a lesioned area as a function of estimatedtemperature distribution across a portion of the simulated tissue.

Alternatively or additionally, intermediate results may be extrapolatedand the geometric surface then may change according to conditionsestimated by extrapolation. For example, after heating by the catheterprobe is stopped, the cooling may be measured for a short while, and thesimulation may show the cooling to continue even after no furthermeasurements are taken, based on extrapolation of the temperaturemeasurements taken. Similarly, late stages of scarring may be presentedbased on extrapolations of measurements indicative of early stages ofscarring.

In some embodiments, simulation comprises simulating a thermal effect oflesioning on the tissue, optionally based on patient specific thermalcharacteristics. Optionally, thermal stimulation effects comprisecoloring according to a probe heat level and/or a heat propagationcharacteristic of a tissue.

Alternatively or additionally, the simulation comprises simulatingtissue properties. Simulated tissue properties may include, for example,texture profile, e.g. a presence of connective tissue and/or muscletissue and/or arteries and/or veins. Alternatively or additionally,simulated tissue properties may include tissue composition, e.g. proteinprofile and/or fiber direction and/or scar presence and/or concentrationof a specific protein, such as for example hemoglobin.

Optionally, patient-specific tissue properties as identified bypre-acquired data, data acquired during the procedure, are graphicallyrepresented using tissue properties. In some embodiments,patient-specific tissue properties include for example fibrosis and/orpatchy fibrosis and/or scars and/or previous ablation lines

Optionally, the ablation is by catheter ablation; for example: RFablation, cryoablation, ultrasound ablation, laser ablation,electroporating ablation, or another form of ablation. Optionally, thetissue to be ablated is a region of atrial wall, for example, regions ofthe left atrial wall around the pulmonary veins for treatment of atrialfibrillation. Optionally, other tissue is ablated, for example, heartmuscle to remove outflow blockage occurring in hypertrophic obstructivecardiomyopathy, neural tissue for treatment by neuromodulation,cancerous tissue for oncological treatment, another tissue, or one ofthese tissues for a different treatment purpose.

In some embodiments, lesion representation, all through its generationand immediately following ablation, conveys animation of intra-tissueproperties. Optionally, temperature progression in 3-D is graphicallypresented based on thermodynamic simulation. In some embodiments,thermodynamic simulation is based on data input such as probe attackangle and/or a quality of an electrode-tissue interface contact area. Insome embodiments, graphical representation of gradually ablated tissueis changed over time, for example, changing color and/or textureappearance, optionally following a predetermined algorithm. In someembodiments, tissue thickening is graphically presented to indicateedema accumulation.

In some embodiments, the method comprises estimating results oflesioning, based on real-time measurements. Optionally, estimatedresults include short-term effects such as heating and/or collateraleffects on nearby tissue and/or reversible block and/or edema.Alternatively or additionally, estimated results include predictions oflong-term effects such as the irreversibility of block.

Reference is now made to FIG. 8, illustrating an ablation overviewpresentation, in accordance with some embodiments of the invention. Insome embodiments, when a catheter is pulled away from an ablationsub-lesion, and/or when a planned ablation is done, and/or when thecatheter is lost, the view shifts automatically to present an overviewof the ablation process being done so far.

Illustrated in FIG. 8 is an inner view of the left and right pulmonaryveins, 602, 604, 606, 608. In some embodiments, an ablation overviewsimulates actual ablation sub-lesions in accordance with theirextrapolated state of advancement since the ablation took place.Optionally, tissue which is estimated to be fully scared is simulated topresent high color intensity, and optionally, a tissue which issimulated to be in an ongoing process, is presented in lower colorintensity, which is correlated with the ablation extrapolated progress.

For example, 802 a and 802 b represent ablation sites where ablation hascompleted Ablation mark 804 represents an ablation site where ablationis in an advanced stage. Ablation mark 806 represents an ablation whereablation is in mid stage. Ablation mark 808 represents simulation ofablation in an initial stage.

Exemplary Neuromodulation

Reference is now made to FIGS. 9A-G, illustrating cardiacneuromodulation simulation, in accordance with some embodiments of theinvention. Optionally, tissue is shown in cross-section, as for examplein FIGS. 9B-9G. Cross-sectional view has a potential advantage forallowing the penetration size to be clearly seen. Additionally oralternatively, in some embodiments of the invention, transparencyeffects are applied to allow seeing into a targeted volume of tissue.

For example, before ablation begins, a local region of tissue selectedby the position of the probe is shown with increased transparency.Optionally, as portions of the tissue become lesioned, they arerepresented in simulated display as more opaque; creating an ablation“island” that directly shows the progress of lesioning. A potentialadvantage of this approach is to allow representation of lesioningprogress from any arbitrary 3-D point of view including the targetedtissue region.

FIGS. 9B-9D represent visually rendered cross-sectional view of a tissueregion as viewed when it is being approached and/or contacted byablation catheter 300, as shown in FIG. 9A. In some embodiments,ablation is directed towards ganglia 902. The ablation markings 972-976shown in a tissue depth are similar to the guide markers shown in FIGS.7A-F, wherein the rendered simulated tissue depth region is 972, heatingis simulated by applying material appearance properties relating to heat974 and scarring and/or cooling is simulated by applying materialappearance properties relating to cooling 976. In some embodiments, theuser interface includes a data inset 922 presenting to the surgeon datapertaining to the ongoing procedure.

FIGS. 9E-9G represent a visually rendered cross-sectional view of atissue region as it is penetrated by needle 1070 of an injection probe930 positioned to modulate and/or ablate activity of a ganglion 902using an injected substance 1002. In the respect of allowingvisualization of the effects of a treatment through a volume of tissue,this cross-section is similar to cross-sections of FIGS. 9A-9D showingthe effects of RF ablation. In some embodiments, the distribution ofinjected material 1002 and/or displacement of nearby tissue by injectedmaterial 1002 is determined by one or more parameters includingdiffusion constants, injection volume, viscosity, projectedpharmaceutical effects, etc., reflected in changes to the materialappearance of the surface defined by the 3-D model representing thetissue region. The material appearance properties are optionallyselected to visually trace the modeled distribution of the injectedmaterial 1002, and/or to visually indicate actual and/or intuitively“metaphorical” effects on tissue (e.g., a smoothing of the tissueevocative of relaxation).

Exemplary Validation

In some embodiments, measured dielectric properties of tissue are usedto determine if an ablation lesion meets one or more targeted criteria.For example, in the case of treatment for atrial fibrillation, it isoptionally determined if a lesioned region of tissue is of sufficientsize, continuity, and/or degree of tissue transformation (such as byscarring and/or cellular disruption) to produce an irreversible block ofimpulse conduction. Effective blockage treatment of an irregular impulseconduction disease such as atrial fibrillation potentially fails whenthe blockage is broken or incomplete. Where it encounters a completedlesion, conduction is stopped. However, a gap potentially allows theimpulse to escape into surrounding tissue, where it may contribute to anirregular heartbeat.

Reference is now made to FIGS. 10A-10B, exemplifying a simulation of avalidation procedure, FIG. 10A, and a simulated overview of a pre madeplan when compared to the actual procedure, FIG. 10B.

Optionally, dielectric property measurements are made post-ablation toverify that changes associated with irreversible lesioning haveoccurred. Optionally, the measurements comprise comparison ofpost-ablation measurements with pre-ablation measurements. In someembodiments, once a validation tool 1030 identifies a gap in conductionblockage, material appearance of the validation overview is modified atthe gap site, optionally by modifying the appearance of marking 620, forexample by changing its color 1062.

In some embodiments, the sequence of preplanned position targets 620 iscompared to the positions of actual targets 802 (e.g., tracked by acatheter tracking system) of an ablation catheter where it performsablation. Optionally, the comparison occurs during an ablationprocedure. In some embodiments, a graphical presentation of the planned620 and actual ablation targets 802 is presented by being projected ontothe patient-specific surface defined by the 3-D model representing thetissue region.

In some embodiments, a user interface also provides summary of theprocedure, having data compared between planned and actual ablation1022, and/or data describing the procedure itself 1024, and/orcalculated compatibility between planned and actual 1026.

Exemplary System

An aspect of several embodiments of the invention relates to a systemfor matching guide markers with a 3-D model of tissue of a patient byupdating the material appearance of the shape defined by the 3-D model,in accordance with some embodiments of the invention.

Reference is now made to FIG. 13, showing a block diagram of a systemfor sensing catheter-tissue relations and simulating such by rendering atissue 3-D model. Illustrated below are potential catheter-tissuerelations, which are useful in some embodiments of the invention.

Position data: In some embodiments (optionally), position data is sensedby use of an electromagnetic field navigation subsystem, comprising bodysurface electrodes 5, field generator/measurer 10, position analyzer 20,and catheter probe sensing electrodes 3. The electromagnetic fieldnavigation subsystem operates by inducing at least one time-varyingelectromagnetic (EM) field 4 (for example, three crossed EM fields)across a region of body 2 including a body tissue region 3 which istargeted to be navigated by catheter 9 and catheter probe 11. Typically,the time varying EM field is induced with a total inter-electrodevoltage of one volt or less, at a frequency of between about 10 kHz andabout 1 MHz. Voltages sensed at different positions by sensingelectrodes 3A are characteristic of corresponding intrabody positions,allowing conversion by position analyzer 20 of voltage measurements toposition information (for example, after exploration of an intrabodyregion 3 using the probe 11, and/or initially based on EM fieldssimulated with respect to a particular configuration of electrodes andanatomical data 31).

Imaging data: Additionally or alternatively, in some embodiments, thereis provided an imaging modality 6 that is configured during use tomonitor at least one characteristic of the body tissue region 3 thatoptionally comprises position information of the probe and/or of tissueaffected by operation of the probe. In some embodiments, the imagingmodality is in continuous, real-time (e.g., 5, 10, 15, 20, 30, 60 ormore images per second) use during at least some phase of a procedure.For example, the imaging modality 6 comprises ultrasound or fluoroscopy.Optionally, system 1 continuously processes changes in images forimmediate display at user interface 55.

Additionally or alternatively, in some embodiments, an imaging modality6 operates more infrequently (for example, once every minute to everyfive minutes, or at another interval). Though not immediately updating,slower imaging modalities 6 are optionally used for providing periodic“key frames” that are useful to synchronize and/or verify display ofsimulated and/or extrapolated states of tissue region 3 and/or catheter9.

Dielectric property sensing: In some embodiments, dielectric propertymeasurements providing indications of tissue state are made bydielectric property analyzer 22 using sensing electrodes 3A (or a subsetthereof) to sense impedance behavior of electrical fields generated inconjunction with field generator/measurer 10, and optionally bodysurface electrodes 5. In some embodiments, dielectric property sensingis used to distinguish, for example, the state of tissue as healthy orfibrotic. Dielectric property sensing for this and other properties isdescribed, for example, in International Patent Application No.IB2016/052690, the contents of which are incorporated by referenceherein in their entirety.

General sensing: In some embodiments, other sensor information (sensedby optional other sensor(s) 14 on catheter probe 11) is used asinteraction data. For example, a force sensor provides information oncontact between a catheter probe 11 and its environment—that it hashappened, and optionally with what degree of force. Additionally oralternatively, contact and/or contact force information is provided fromsensing electrodes 3A in conjunction with other elements of the EM fieldnavigation subsystem, based on impedance measurements. In someembodiments, other sensor(s) 14 comprise a temperature sensor, flowsensor, and/or another sensor configured to provide information aboutthe environment of the catheter probe 11.

Treatment interactions: In some embodiments, a treatment element 8 isprovided on catheter probe 11. The interaction data optionally comprisesinformation about the operation of the treatment element and/orcomponents controlling its effect.

The treatment element 8 is optionally a probe for ablation treatment;for example by radio frequency ablation, cryoablation, microwaveablation, laser ablation, irreversible electroporation, substanceinjection ablation, and/or high-intensity focused ultrasound ablation.In some embodiments, treatment element 8 is also used as a sensingelectrode 3A (for example, in RF ablation, a treatment deliveryelectrode may also be used to sense the effect of local dielectricproperties on measured electrical field impedance). Optionally,treatment element 8 is operated in conjunction with a treatmentcontroller 13, configured to provide treatment element 8 with functionssuch as power, control and/or monitoring.

In some embodiments, the treatment element 8 is configured to deliveranother treatment (for example, temporary activation or inactivation)using heat, cold, electrical current, sound radiation and/or lightradiation. Optionally, the treatment element 8 comprises an injectionapparatus, used to inject a treatment substance, and/or a substance usedin diagnosis such an imaging tracer. In some embodiments, the injectedsubstance comprises ethyl alcohol, Botox, living cells, and/or growthfactor. Optionally, the injected substance comprises a radiolabeledsubstance, an immunosubstance, and/or a radiopaque trace substance.

Interaction data relating to the interactions of a treatment element 8with a tissue region 3 comprising target sites for a procedure include,for example, duration of operation, time of operation, power and/orfrequencies of energy delivered, nature and/or concentration ofsubstances delivered, and/or quantities of substances delivered.Optionally, operational settings are combined with information abouttreatment element position and/or environment in order to deriveinteraction data.

It should be understood that not every source of interaction datadescribed in relation to FIG. 13 is necessarily implemented in everyembodiment of the invention. Preferably, there is provided inembodiments of the invention at least a position sensing modality and amonitored treatment modality.

Assignment of MAPs to Shapes Defined by a 3-D Model

In some embodiments of the invention, material appearance properties areassigned based on the output of one or more simulators 1110 (FIG. 11).

In some embodiments, sensing data 1101 and/or treatment status data 1102are used directly or indirectly as input to one or more simulationmodules 1110 (e.g., modules 1111, 1112, 1113, and/or 1114) which makeadjustments to a modeled appearance state 1120 of the tissue based oninputs received, and one or more simulated aspects of tissue physiology,shape, and/or mechanics. Simulators 1110 also optionally receive asstarting input anatomical data 31 and/or tissue state data 1104. Inaddition to adjusting the modeled appearance state 1120, simulators 1110optionally maintain their own internal or mutually shared simulationstates.

Reference is now made to FIG. 11, wherein different methods of providingprobe interaction input to simulators 1110 are described.

Direct sensing input: In some embodiments, basic simulation isimplemented based directly on sensing data 1101. For example, atemperature reading from a temperature sensor 14 is optionally mappeddirectly to a color change selected according to the measuredtemperature. Additionally or alternatively, in some embodiments, a moreinvolved simulation is performed: wherein probe interaction with avirtual material representing tissue is, in at least one aspect,physically and/or physiologically simulated in order to produce a newmodeled appearance state.

Physiologically interpreted sensing input: In some embodiments, the useof sensing data 1101 by a simulator is indirect after interpretation byone or more physiology trackers 1106. Physiology tracker 1106, in someembodiments, is a module which accepts sensing data 1101 and converts itto an assessment of current physiological state. For example, in someembodiments, sensing data 1101 comprises dielectric measurements thatphysiology tracker 1106 is configured to convert into assessment oftissue state, for example as described in International PatentApplication No. IB2016/052688, the contents of which are included byreference herein in their entirety. Additionally or alternatively,electrical activity indicating a functional state of the tissue itselfis measured.

The output of the physiology tracker 1106 from one or more of theseinputs is optionally in terms of one or more states such as lesiondepth, lesion volume, degree of lesion transmurality, characterizationof tissue edema, characterization of functional activity and/orinactivation, a classification as to a potential for tissue charring,and/or a classification as to a potential for steam pop. These outputsare optionally provided to a physiology simulator 1114 or an ablationphysics simulator 1112, configured to convert such states into MAPs thatindicate the state calculated from the measurements. Optionally, theinterpreted tissue state also affects mechanical properties assumed, forexample, by a contact physics simulator 1111 and/or an injectionsimulator 1113. It is a potential advantage to implement a physiologicaltracker 1106 as a distinct module which can be treated as acomputational “service” to any appropriate simulator 1110. However, itshould be understood that physiological tracker 1106 is optionallyimplemented as part of one or more simulators 1110 producing changes toa modeled appearance state 1120. In this case, the module configurationis more like that of direct sensing input, with the simulation ofappearance integrated with physiological interpretation of the sensingdata.

Positionally interpreted sensing input: In some embodiments, the use ofsensing data 1101 by a simulator is indirect after interpretation by aprobe position tracker 1107. Probe position tracker 1107, in someembodiments, is a module which accepts appropriate sensing data 1101(e.g., electromagnetic field tracking data, acoustic tracking data,and/or imaging data) and converts it to a determination of the position(e.g., location and/or orientation) of a probe such as catheter probe11.

Optionally position determination includes determination of tissuecontact force and/or quality, using a force sensor on the probe, and/orfor example as described in International Patent Application No.IB2016/052686, the contents of which are included by reference herein intheir entirety. Additionally or alternatively, on-line imaging data(e.g., ultrasound and/or angiographic images) are used, intermittentlyand/or continuously, to determine and/or verify probe position.

Probe position determinations are optionally used as inputs to any ofthe simulators 1110; for example in order to assign particular positionsto measurements of other tissue states/properties, and/or to helpcharacterize changes induced by probe interactions with tissue (e.g.distortions of tissue shape, and/or simulated effects of treatmentprocedures). It is a potential advantage to implement probe positiontracker 1107 as a distinct module which can be treated as acomputational “service” to any appropriate simulator 1110. However, itshould be understood that probe position tracker 1107 is optionallyimplemented as part of one or more simulators 1110 producing changes toa modeled appearance state 1120.

Treatment status input: In some embodiments, simulation is implementedbased on treatment status data 1102. Optionally, treatment status datais applied directly to modeled appearance state; for example, as a markat each position of activation treatment modality activation.Additionally or alternatively, in some embodiments, at least one aspectof the tissue and/or tissue/probe interaction is physically and/orphysiologically simulated in order to produce a new modeled appearancestate, based on the treatment status data. For example, in someembodiments, a physiology simulator 1114 receives input indicating thata probe-delivered treatment operation has occurred at some particularposition (optionally along with parameters of the treatment operation).Physiology simulator 1114 is optionally configured to model the reactionof tissue to the treatment, instantaneously (for example, due directlyto energy delivered by an ablation treatment), and/or over time (forexample, as an edematous reaction develops in the minutes following anablation treatment). In another example, an injection simulator 1113receives treatment status input indicating that a material injection isoccurring. Injection simulator 1113 is optionally configured to model anappropriate reaction of tissue to the injected substance (e.g., ablationand/or inactivation). The reaction is optionally immediate, and/orincludes a slow-developing component as the material diffuses from theinjection site. Optionally, changes in shape due to the addition ofmaterial volume to the tissue are also modeled.

Use of a Graphical Game Engine in Real-Time Anatomical Navigation

Reference is now made to FIG. 12, which schematically representscomponents, inputs, and outputs of a graphical game engine 1200operating to manage and render scene elements 1220 to motion frame-rateimages 1240, according to some embodiments of the present disclosure.

In some embodiments of the invention, a graphical game engine 1200 isused not only to render images, but also to provide more generally thedata structure and code framework of the “scene” and how it changes inresponse to time and input.

In broad outline, a graphical game engine 1200 comprises a collection ofcomputer software components exposing one or more applicationprogramming interfaces (APIs) for use in describing, instantiating(initializing and maintaining), continuously updating, rendering, and/ordisplaying of scene elements 1220. The scene elements 1220 provided forthe operations of graphical game engine 1200 optionally include, forexample, descriptions of terrain 1221, objects, 1222, cameras 1223,and/or lighting elements 1222. Definitions are optionally expressed interms of geometrical-type scene data 1225 (e.g. model assets, shapes,and/or meshes), and/or appearance-type scene data 1226 (e.g., imageassets, materials, shaders, and/or textures). In some embodiments, 3-Dmodel 1221 and material appearance properties (MAPs) data are initiallyproduced already in a format which is directly used by graphical gameengine 1200.

In some embodiments, scene elements 1220 are provided with simulateddynamic behaviors by an iterated series of calculated scene adjustments1210. The scene adjustments 1210 are optionally implemented by a varietyof software components for e.g., motion physics 1212, collisiondetection 1213, and/or scripts 1211. These are examples; graphical gameengines 1200 optionally implement additional services, e.g.,“destructibility”. Scripts 1211 can be provided to simulate, forexample, autonomous behaviors and/or the effects of triggered events.Scripts 1211 are optionally written in a general-purpose computerlanguage taking advantage of APIs of the graphical gaming engine 1200,and/or in a scripting language particular to an environment provided bythe core graphical gaming engine 1200. Graphical gaming enginesoptionally also accept integration with plugin software modules(plugins, not shown) which allow extending the functionality of the coregraphical game engine 1200 in any of its functional aspects. Forpurposes of the descriptions provided herein, plugins which performfunctions related to updating the scene state are also encompassedwithin the term “script” 1211.

For purposes of descriptions herein, the scripts (optionally includingplugins) 1211 and scene elements 1220 are considered part of thegraphical game engine 1211 as a functional unit. Optionally, forexample, where reference is made particularly to the off-the-shelfgraphical game engine apart from specialized adaptations for usesdescribed herein, the term “core graphical game engine” is used.

For interactivity, graphical game engines 1200 accept user input 1214(optionally including, but not limited to, inputs from devices such asmouse, keyboard, touch screen, game controller, hand motion detector;and for some embodiments of the current invention, optionally includinginputs describing probe positions, treatment activation, etc.).

A typical graphical game engine also includes a rendering pipeline 1230that may include one or more stages of 3-D rendering, effectsapplication, and/or post-processing, yielding at least one stream offrame-rate images 1240. In some embodiments, the stages of the renderingpipeline 1230 include modules which implement simulated opticalalgorithms—not necessarily directly based on real-world physicallaws—generally selected to produce a rendered result which visuallygives to elements in the rendered scene the appearance of materialsubstances.

Table 1 includes some examples of how graphical game engine features andconcepts are optionally used in some embodiments of the currentinvention.

TABLE 1 Examples of Graphical Engine Feature/Concept UsageFeature/Concept Examples of Use Scene 1220 Overall visually renderablemodel of environment and objects within it. Terrain 1221 Optionally usedto represent geometry (i.e., shape) of the anatomical environment.Objects 1224 Probe 11 is optionally represented as a “game” object, andmay optionally serve as a viewpoint anchor like avatars and/or tools incertain 3-D games. Significant features of the anatomical environmentsuch as scars, lesions, and/or regions of edema, are optionallyimplemented as appropriately positioned objects, e.g., embedded in anenvironment of surrounding tissue. Guides and markers are optionallyimplemented as game objects. Assets 1225, Tissue, probe, guide, and/orother objects and/or their 1226 appearances are optionally instantiatedfrom assets which represent available types of objects, their behaviorsand/or their appearances. Cameras 1223 Cameras optionally defineflythrough viewpoint(s) of the anatomy traversed by the catheter probe11, and/or overview viewpoint(s) (showing probe and tissue from a remoteviewpoint). Optionally, the position of catheter probe 11 defines one ormore camera viewpoints by its position/or orientation. Lighting 1222 Inaddition to providing general lighting of the tissue being navigated,lighting 1222 is optionally defined to provide highlighting, e.g., ofregions pointed at by the probe 11, indications of environmental stateby choice of light color, light flashing, etc. Lighting is optionallyused to implement MAPs non-locally (that is, a defined light sourceoptionally is defined to illuminate simulated tissue to selectivelychange its material appearance, while not being part of the materialproperties of appearance of the simulated tissue as such). Image Assets;MAPs which are also material properties of Materials, appearance, forexample, defining the appearance of Shaders, and tissue as healthymuscle, edematous, fibrotic, heated, Textures 1126 cooled, etc. ParticleType of object optionally used for providing effects Systems such assmoke/steam-like indications of ablation heating, spray, transfer ofenergy, etc. Collision Optionally used for interactions between probeand Detection the geometry (shape) of the anatomical environment; 1213and Motion optionally including deformation of the probe and/or Physics1212 the anatomy. As implemented by core graphical game engines, theterm “physics” generally is limited to physics affectingmovement/deformation of game objects such as collision, gravity, ordestruction. Scripts 1211 Optionally used for animating and/or showingchanges in dynamic features of the environment (lighting, terrain), view(camera position) and/or game objects: for example, development oflesions, development of edema, heating/cooling effects, and/or injectioneffects. Optionally, scripts are used to implement dynamic appearance,even though the underlying state representation is constant (e.g.,coruscating and/or pulsing effects). User Game Input Optionally compriseinputs reflecting changes in probe 1214 position for guiding navigationthrough the scene, and/or determining camera position. MultiplayerDuring a procedure, there is optionally a plurality of differentsurgeons working simultaneously with a system according to someembodiments of the current invention. For example, while a primaryphysician manipulates the probe, one or more additional workers areoptionally reviewing the simulated environment to locate next targetsites for the probe, evaluate effects of previous ablations, etc.Optionally, there is more than one probe in use at a time, each of whichis optionally treated as a different “player” with its own associatedcamera views and/or interaction capabilities.

Procedure-Simultaneous Mapping

Reference is now made to FIG. 14A, which is a flow chart schematicallydescribing a cardiac ablation procedure, wherein indicating marks areplaced on a 3-D model which is developed from data obtained during theprocedure itself, according to some embodiments of the presentdisclosure. Reference is also made to FIGS. 14B-14E, which show a phaseof iterative intra-procedure reconstruction of a model 1500 of a rightatrium 1510 and connecting blood vessels including the superior venacava 1520 and inferior vena cava 1524, according to some embodiments ofthe present disclosure. Additional blood vessels represented by 3-Dmodel 1500 are identified in FIG. 15. A catheter probe 1504 is alsoindicated at various positions within model 1500; this is a displayrendering corresponding to an actual catheter probe moving within theright atrium 1510 being mapped, put in register with model 1500according to the position of the distal end of the actual catheterprobe. The actual catheter probe corresponding to catheter probe 1504 isalso the probe used in mapping right atrium 1510.

For purposes of description, the general plan of the procedure ispresumed known in advance (e.g., to ablate in the left atrium using anablation catheter), and it is also presumed that details of targetanatomy such as shape remain unknown until the performance ofintracardiac mapping using an intrabody probe. In some embodiments, the3-D model is completely generated from the current procedure'sintracardiac mapping data. However, methods encompassing variations fromthese presumptions are also envisioned as belonging to some embodimentsof the present invention; and may be implemented by one of ordinaryskill in the art, changed from the descriptions herein as necessary. Inparticular, it is to be understood that in some embodiments, imagingdata, atlas data, and/or previously acquired intracardiac mapping dataare used to provide a starting point for a 3-D model, which is thendetailed based on further intracardiac mapping data acquired. In someembodiments, another type of cardiac mapping and/or imaging is performedduring the procedure.

It is also presumed, for purposes of description, that the mapping probeis an electrode probe, that the ablation probe is an RF ablation probe;and moreover that the two probes are optionally (and as described) thesame probe. However, methods encompassing variations from thesepresumptions are also envisioned as belonging to some embodiments of thepresent invention; and may be implemented by one of ordinary skill inthe art, changed from the descriptions herein as necessary. It is to beunderstood, for example, that the method is optionally carried out usingone or more different probes, wherein the probe or probes in aggregateprovide an anatomical mapping function and a treatment function.Adjustments of the method as necessary to apply to other organs andprocedures are also considered embodiments of the present invention.

The flowchart begins, and at block 1402, in some embodiments, anintrabody probe is positioned in a region of the body (e.g., a cardiacchamber) containing tissue targeted for treatment; for example, within aleft atrium comprising tissue target for ablation. In some embodiments,the probe is a catheter probe, and combines one or more electrodesuseful for electrical field-based intrabody mapping with an electrodefor ablation (optionally also used as one of the mapping electrodes),e.g., RF ablation.

At block 1404, in some embodiments, the probe is moved within thecardiac chamber, recording mapping data indicating interior surfacedetails of the chamber wall while doing so. During the movements, a 3-Dmodel of the cardiac chamber is gradually built from this data (e.g.,using a suitably configured computer which receives the data), to alevel of detail suitable to make at least an initial determination ofone or more target regions for ablation. The 3-D model is displayedusing a display of user interface 55, optionally being updated as itdevelops based on mapping data obtained over the course of theprocedure.

At block 1406, in some embodiments, an initial treatment plan (e.g., aninitial ablation plan) is generated. The plan may comprise elements, forexample as described in relation to any of the preplanning, planning,and plan adjustment methods herein. For example, the plan may comprise aline along which ablation is planned to be performed, and/or a pluralityof targeted sites (e.g., along the line) at which ablation isparticularly planned to be carried out (e.g., by delivery of RF energyduring contact between the ablation probe and the targeted tissue).Optionally, the plan is formed automatically by computer based on thegeneral goal of the procedure and the details of known anatomy. Forexample, once the positions of pulmonary veins which are to beelectrically isolated from tissue of the left atrium are known, thecomputer calculates the course of an ablation line surrounding them,optionally also particular sites along the ablation line at whichablation is to be performed, and optionally parameters of ablation likepower and duration of ablation at those sites. In some embodiments, theautomatic plan is adjustable by manual intervention (e.g., using userinterface 55). In some embodiments, a user provides at least part ofplan (e.g., a general course of an ablation line) manually. In someembodiments, planning comprises selection of one or more treatment sitesusing an orientation (pointing selection) and/or a contact of the probe(touching selection) with tissue to be treated. Optionally there isautomatic adjustment and/or detailing of the manual plan as necessary.

At block 1408, in some embodiments, marks indicating aspects of the planand/or status of the procedure (e.g., progress made, current probeposition and/or orientation) are rendered. Examples of status of theprocedure may include: progress made so far, current probe positionand/or orientation, etc. The aspects of the plan and/or status of theprocedure are optionally rendered upon the displayed surface of the 3-Dmodel, and/or in conjunction with a volume of tissue represented by the3-D model; for example, as described in relation to any one or more ofFIG. 1A-1E, and/or as shown in figures herein, for example, as ablationlines and targeted ablation sites (e.g., as in FIGS. 6A-6E), state ofablation in progress (e.g., as in FIGS. 7A-7F), tissue state indications(e.g., indications of edema), and/or indications of probe positionand/or orientation (e.g., as in FIGS. 3A-5D).

At block 1410, in some embodiments, further mapping data is recorded,and the heart chamber 3-D model updated in its shape (geometry)accordingly, for example as described in relation to block 1404.

FIG. 14B-14E show interim results of 3-D model updating from probe-basedmapping data obtained within a right atrium 1510. It should be notedthat features may be identified with a first shape during an earlierphase of the mapping, then refined, later on, to a more accurate and/ordetailed shape on the basis of further information. This illustrates onereason why it is a potential advantage to have an accurate reference formonitoring and evaluating a procedure plan concurrently with the updatedcollection of 3-D model data representing the body region within whichthe procedure plan is actually carried out.

At block 1412, in some embodiments, data indicating operation of theablation probe or another treatment device is optionally recorded.

At block 1414, in some embodiments, the plan generated at block 1406 isoptionally adjusted, refined, and/or replaced, according to the datarecorded in blocks 1410 and/or 1412. The adjustment can be, for example,as described to achieve any of the plan adjustment purposes describedherein, for example, in relation to FIG. 2, and/or as described in theOverview.

From block 1416, in some embodiments, as long as the procedure continuesand/or the probe remains within the heart chamber targeted for mappingand/or treatment, flow next returns to block 1408 for redisplay of thecurrent plan and/or procedure state. Otherwise, the flowchart ends.

Probe Position Indicating Marks

Reference is now made to FIG. 15, which illustrates use of indicatingmarks 1501, 1502 for showing a current position of a tip 1505 of a probe1504 positioned within a 3-D model 1500 of a body lumen, according tosome embodiments of the present disclosure. The body lumen modeledcomprises a region of a right atrium 1510 interconnecting between asuperior vena cava 1520 and an inferior vena cava 1524. Also shown are ahepatic vein 1526, region of renal vein buds 1528, and coronary sinus1522. The position, including orientation, and movements of probe 1504within 3-D model 1500 are synchronized to actual movement of the probewithin a body lumen corresponding to 3-D model 1500.

Two indicating marks 1501, 1502 are shown, each mapped to a surface of3-D model 1500. The center point of mark 1501 shows the position atwhich a longitudinal axis extending distally from probe 1504 (that is,an axis extending distally along a facing direction of a distal portionof probe 1504) intersects the surface of model 1500. The center point ofmark 1502 is centered on a surface point of 3-D model 1500 which isclosest to a point at the tip 1505 of probe 1504.

During a procedure, the marks 1501, 1502 are moved around, eachaccording to their respective placement rule, as data indicating the newposition, including orientation, of probe 1504 are received. The marks1501, 1502 are placed on the surface of model 1500 so that they conformto the surface shape as described, for example, in relation to FIGS.3A-5D. Mark 1502 appears foreshortened, for example, because of theorientation of the surface portion which it occupies. Optionally, marks1501, 1502 are distinguished by one or more of color, shape, and size.For example, mark 1501 is optionally a red mark, while mark 1502, isoptionally a blue mark. Optionally, size of marks 1501, 1502 varies withdistance from the probe 1504; for example, size is optionally chosen tomaintain a fixed angular size (or fixed angular size with offset,similar to a flashlight beam emanating from an extended source) withrespect to an origin located at some reference location defined by theposition of probe 1504. Optionally, when the placement rules of mark1501 and 1502 result in positions that substantially coincide, and/orwhen probe 1504 is determined to be positioned touching a surface ofmodel 1500, a combined mark (not shown) is used, optionally with adistinction in size, shape, and/or or color; for example, a green color.

Any one or both of indicating marks 1501, 1502 are optionally simulatedas a surface feature of a 3-D model (e.g., modeled by changing amaterial property of appearance of the surface such as absorption,scattering, glowing, and/or reflectance), and/or as an illuminatedsurface portion of a 3-D model (e.g., a “flashlight” type beam and/or ashape of a beam projected as if from a shaped light source; for example,similar to the effect of light projected from a focused image plane or apattern-scanning point source).

Potential advantages relating to effects on how a procedure is performedfor, e.g., an indicating mark such as indicating mark 1501 in discerningorientation of a probe relative to a pointed-at surface are discussed inthe Overview, herein. A potential advantage of the combined use of marks1501 and 1502 is to assist in coordinating contact with orientationduring manipulation of a catheter probe to reach, e.g., a treatmentsite. As the probe approaches the surface, the rules governing renderingof the two marks 1501, 1502 are such that the closer together the twomarks 1501, 1502 are at a certain distance, the closer (in many but notall cases) the probe will be to an orthogonal approach to the surfacebeing approached. Also, during probe manipulation, “what surface isnearest” and “what surface is pointed at” may be simultaneously and/oralternatively of interest. For example, when a probe is oriented towarda distant surface location, it may be relatively safe to advance theprobe quickly along a vessel or other nearby surface in order to obtainmapping points along a larger extent more quickly. The surface can beselected by moving the probe while observing the position of indicatingmark 1502, and the selection of a clear path for advancing the probe canbe performed by at the same time controlling the position of indicatingmark 1501 to target a distant surface position.

General

As used herein the term “about” refers to ±25%. The terms “comprises”,“comprising”, “includes”, “including”, “having” and their conjugatesmean “including but not limited to”.

The term “consisting of” means “including and limited to”.

The term “consisting essentially of” means that the composition, methodor structure may include additional ingredients, steps and/or parts, butonly if the additional ingredients, steps and/or parts do not materiallyalter the basic and novel characteristics of the claimed composition,method or structure.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise.

Throughout this application, various embodiments of this invention maybe presented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible subranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween.

As used herein the term “method” refers to manners, means, techniquesand procedures for accomplishing a given task including, but not limitedto, those manners, means, techniques and procedures either known to, orreadily developed from known manners, means, techniques and proceduresby practitioners of the chemical, pharmacological, biological,biochemical and medical arts.

As used herein, the term “treating” includes abrogating, substantiallyinhibiting, slowing or reversing the progression of a condition,substantially ameliorating clinical or aesthetical symptoms of acondition or substantially preventing the appearance of clinical oraesthetical symptoms of a condition.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination or as suitable in any other describedembodiment of the invention. Certain features described in the contextof various embodiments are not to be considered essential features ofthose embodiments, unless the embodiment is inoperative without thoseelements.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

It is the intent of the Applicant(s) that all publications, patents andpatent applications referred to in this specification are to beincorporated in their entirety by reference into the specification, asif each individual publication, patent or patent application wasspecifically and individually noted when referenced that it is to beincorporated herein by reference. In addition, citation oridentification of any reference in this application shall not beconstrued as an admission that such reference is available as prior artto the present invention. To the extent that section headings are used,they should not be construed as necessarily limiting. In addition, anypriority document(s) of this application is/are hereby incorporatedherein by reference in its/their entirety.

What is claimed is:
 1. A method of visually rendering a 3-D model of atissue region to indicate a position and a facing direction of acatheter probe during a catheterization procedure, the methodcomprising: determining said position and facing direction of a distalend of said catheter probe with respect to said tissue region; andrendering said 3-D model to include a simulation of a first indicatingmark, said first indicating mark being simulated in a position of asurface portion defined by said 3-D model, wherein the position is alsolocated along an axis extending distally from said determined positionand in said determined facing direction of said distal end of saidcatheter.
 2. The method of claim 1, further comprising rendering said3-D model to include a simulation of a second indicating mark, saidsecond indicating mark being simulated in a position of a second surfaceportion defined by said 3-D model, wherein second surface portionoccupies a closest surface position of said 3-D model to a predefinedportion of said distal end of said catheter.
 3. The method of claim 2,wherein the first indicating mark and the second indicating mark arerendered together as a single indicating mark when the determinedposition of the distal end indicates contact with a surface defined bythe 3-D model.
 4. The method according to claim 1, wherein at least oneof the indicating marks is shaped and positioned to congruently matchthe corresponding 3-D model surface portion.
 5. The method according toclaim 1, wherein said 3-D model is rendered as viewed from a viewpointfrom outside an organ comprising the tissue region.
 6. The methodaccording to claim 1, wherein said 3-D model is rendered as viewed froma viewpoint from within an organ comprising the tissue region.
 7. Themethod according to claim 1, wherein said tissue region comprises a bodylumen.
 8. The method according to claim 1, wherein said 3-D model isrendered as viewed from a viewpoint offset to said distal end of saidcatheter probe.
 9. The method according to claim 1, wherein saiddetermining and said rendering is provided iteratively during at least aportion of said catheterization procedure.
 10. The method according toclaim 1, further comprising simultaneously presenting two or more viewsof said 3-D model, each viewed from a different viewpoint, the differentviewpoints comprising a first viewpoint being inside an organ comprisingsaid tissue region and a second viewpoint being outside said organ. 11.The method of claim 10, wherein both presentations include said firstindicating mark.
 12. The method according to claim 1, wherein at leastone of indicating marks is simulated as an illumination of the 3-D modelsurface.
 13. The method according to claim 12, wherein said illuminationis simulated to be uneven across a simulated illumination beam.
 14. Themethod according to claim 12, wherein a center of said illumination iscalculated according to a position and facing direction of the catheterprobe relative to the tissue region.
 15. The method according to claim14, wherein the center of illumination is graphically presented byincreased illumination intensity at a center of said beam.
 16. Themethod according to claim 12, further comprising simulating a secondillumination source illuminating from a position distinct from theposition of the distal end of the catheter probe.
 17. The methodaccording to claim 12, further comprising simulating a secondillumination source, illuminating in a direction distinct from thefacing direction of the distal end of the catheter probe.
 18. The methodaccording to claim 17, wherein said second illumination source issimulated as an ambient light source.
 19. The method according to claim12, wherein said rendering comprises selecting a material appearance ofa surface of said tissue region, said material appearance is simulatedto be affected by the illumination.
 20. The method according to claim12, wherein said rendering comprises rendering said tissue region as atleast partially translucent to said simulated illumination. 21.Apparatus for visually rendering a 3-D model of a tissue region toindicate a position and a facing direction of a catheter probe during acatheterization procedure, the apparatus comprising: a non-transitorycomputer readable medium storing program instructions; at least onehardware processor in communication with said non-transitory computerreadable medium, that when said instructions are executed by said atleast one hardware processor, said execution causes said at least onehardware processor to: (a) determine said position and facing directionof a distal end of said catheter probe with respect to said tissueregion; and (b) render said 3-D model to include a simulation of a firstindicating mark, said first indicating mark being simulated in aposition of a surface portion defined by said 3-D model, wherein theposition is also located along an axis extending distally from saiddetermined position and in said determined facing direction of saiddistal end of said catheter.